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                           ALOC1

Allocation 1 Table.  This non-resident table,  the  size  of
the OFN area in SPT, is used to help enforce disk quotas for
each active directory.

Defined in:  STG

Reference by:  PAGEM
                        
Index:  ALOCX portion of an OFN entry in the SPT


                                Format

        +-------------------------------------------------------+ / \
ALOC1:  |  ADIRN                    |  ODIRC                    |  |
ALCWD   |       Directory No.       |    OFN Directory Count    |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           | NOFN
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \  |
        +-------------------------------------------------------+ \ /


Note:  Each SPT entry in the OFN area contains an index into this
       table.
                                                      Page 2


                           ALOC2

Allocation 2 Table.  This non-resident table,  the  size  of
the  OFN  area is SPT, is used in disk quota enforcement for
each active directory.

Defined in:  STG

Referenced by:  DISC, PAGEM

Index:  ALOCX portion of an OFN entry in the SPT


                                Format

        +-------------------------------------------------------+ / \
        |  PGLFT                                                |  |
ALOC2:  |        Count of Pages Left for This Directory         |  |
        |                 (may be negative)                     |  |
        |-------------------------------------------------------|  |
        |                           .                           | NOFN
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \  |
        +-------------------------------------------------------+ \ /


        Note:  Each SPT entry in the OFN area contains an index 
               into this table.
                                                      Page 3


                            BAT

Bad Allocation Table.  The BAT Block is one sector in length
(128  words).  It consists of 4 words of header, followed by
data;  each 2 word data entry indicates the bad spots on the
disk.

Defined in:  PROLOG

Referenced by:  DSKALC, DISC, DEVICE, PHYH2

                                Format

          +-------------------------------------------------+  --
BATNAM=0  |                   SIXBIT/BAT/                   |   |
          |-------------------------------------------------|   |
          | BATFR                  |                        |   |
BATFRE=1  |      Free Blocks Left  |                        |   |
          |-------------------------------------------------|   |
          |          |9  BTHCT   17|                        |
          |          | # of Pairs  |                        | Header
          |          |   Added By  |                        |
          |          |    Mapper   |                        |   |
          |-------------------------------------------------|   |
          |  BTMCT                                          |   |
          |           # of Pairs Added by Monitor           |  --
          |-------------------------------------------------|  --
          |              Bad Block Information              |*  |
          |-------------------------------------------------|   |Data
          |          |9   ADD27                          35 |*  |Pair
          |          |   Address of Starting Sector         |   |
          |-------------------------------------------------|  --
          |                        .                        |
          |                        .                        |
          |                        .                        |
          |                        .                        |
          |                        .                        |
          \                        .                        \
          |-------------------------------------------------|  --
          |                                                 |   |
          |-------------------------------------------------|   |Data
          |                                                 |   |Pair
          |-------------------------------------------------|  --
BATCOD=176|              Unlikely Code 606060               |
          |-------------------------------------------------|
BATBLK=177|         Sector Number of the BAT Block          |
          +-------------------------------------------------+
                                                      Page 4


     Data Pair  0         8            18       20  21  22           35
              +---------------------------------------------------------+
     word 1   |   BATNB    |          | BTKNM     |    |      APRNM     |
              |Bad Blks Cnt|          |Controller#|Type|   Apr Serial # |
              +---------------------------------------------------------+



                Bits       Pointer          Content

                0-8        BATNB            Count of Bad Blks in Pair
               18-20       BTKNB            Massbus Controller #
                 21        BADT             Type field in BAT Pair
               23-35       APRNM            APR Serial #


     word 2
                Bits     

               18-35       ADD18            Old style disk address of
                                             starting sector
                9-35       ADD27            New style address of
                                              starting sector
                                                      Page 5


        Name:           BTB*

        Description:    Bit Table for Disk.  This table  has
                        mapped  into it pointers to the file
                        STRNAM:<ROOT-DIRECTORY>    DSKBTTBL,
                        when    pages   are   allocated   or
                        deallocated from  the  disk  unit(s)
                        belonging to structure, STRNAM.  The
                        bit  table  file  as   shown   below
                        indicates  which  pages are assigned
                        (bits off) and which  are  available
                        (bits on).

                        It consists of two parts;   the  top
                        half contains   the  number  of free
                        pages  for  each  cylinder  in   the
                        structure   and   the   bottom  half
                        contains a bit map (1 bit per  page)
                        for  all  pages  of each cylinder in
                        the structure.

                        At initialization time, all of  this
                        structure's  pages  belonging to the
                        Home  blocks,  swapping  space   and
                        pointed  to  by  the  BAT blocks are
                        assigned in the Bit Table file.

        Defined in:     STG

        Referenced by:  DSKALC
                                                      Page 6


                               Format

                +-------------------------------------+
                !      Free Pages on Cylinder 0       !
                !-------------------------------------!
                !      Free Pages on Cylinder 1       !
                !-------------------------------------!
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !-------------------------------------!
                !      Free Pages on Cylinder n       !
                !-------------------------------------!
                \                                     \  \
                \                                     \  Cylinder 0
                \                                     \  /
                !-------------------------------------!
                \                                     \  \
                \                                     \  Cylinder 1
                \                                     \  /
                !-------------------------------------!
                !                  .                  ! 
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !                  .                  !
                !-------------------------------------!
                \                                     \  \
                \                                     \  Cylinder n
                \                                     \  /
                +-------------------------------------+
                                                      Page 7


        Note:
           In the bit map each cylinder starts on a word boundary
           and contains as many full words as are needed for all
           of its pages.

          *For Systems which have sectioning, the BTB table does
           not hold the maps for the disk bit table file.  Rather,
           the monitor will map the disk bit table file for a
           structure into section four of the monitor's address
           space when it needs to allocate or deallocate disk pages.
           That is, the index block of this file will be the page
           table pointed to by the monitor's section pointer for
           section four.
                                                      Page 8


                BUG-HLT/CHK/INF-STORAGE-AREA

BUGHLT, BUGCHK, and  BUGINF  Storage  Area.   This  resident
storage  is  used  to hold such information as the push down
list,   PC,   ACs    and    dispatch    address    when    a
BUGHLT/BUGCHK/BUGINF  occurs.   BUGSEB  holds the pointer to
the last queued up SYSERR block.  (See SYSERR-STORAGE-AREA)

Defined in:  STG

Referenced by:  APRSRV, CDRSRV, DEVICE, DIAG, DIRECT, DISC,
                DSKALC, DTESRV, ENQ, FESRV, FILINI, FIMLSC,
                FORK, FREE, FUTILI, GTJFN, IMPPHY, IMPDV,
                IO, IPCF, JSYSA, JSYSF, LINPR, LOGNAM,
                LOOKUP, MAGTAP, MEXEC, MSTR, NETWRK, 
                NSPSRV, PAGEM, PHYH11, PHYH2, PHYM2, PHYP4,
                PHYSIO, SCHED, STG, SWPALC, SYSERR, TAPE
                TTYSRV


                                FORMAT

        +-------------------------------------------------------+
 BUGHLT:|                           0 (PC Stored here on BUGHLT)|
        |-------------------------------------------------------|
        |           JRST BUGHO the BUGHLT was issued            |
        |-------------------------------------------------------|
 SVVEXM:|             Save Valid Examine in BUGTYO              |
        |-------------------------------------------------------|
 BUGLCK:|                Lock on BUGxxx Routines                |
        |-------------------------------------------------------|
 BUGCHK:|                           0 (PC Stored here on BUGCHK)|
        |-------------------------------------------------------|
        |                      JRST BUGCO                       |
        |-------------------------------------------------------|
 BUGINF:|                           0 (PC Stored here on BUGINF)|
        |-------------------------------------------------------|
        |                      JRST BUGIO                       |
        |-------------------------------------------------------|  / \
 BUGACS:|                                                       |   |
        \                 ACs Saved on a BUGHLT                 \  # of
        \          (Contents of ACs at time of BUGHLT)          \  ACS
        |-------------------------------------------------------|  \ /
 BUGPDL:|                    Push Down List                     |  / \
        \                                                       \ BUGPLN
        \                                                       \  (12)
        |-------------------------------------------------------|  \ /
 BUGCNT:|          Count of BUG Blocks in SYSERR Queue          |
        |                 (Maximum of BUGMAX=5)                 | 
        |-------------------------------------------------------| 
 BUGNUM:|        Number of BUGHLT/CHK/INFs since STARTUP        |
        |-------------------------------------------------------|
 BUGSEB:|          Ptr to last queued up SYSERR Block           |
        |                due to a BUGHLT/CHK/INF                |
        |-------------------------------------------------------|
                                                      Page 9


 BUGP:  |        Place to Store P During BUG HLT/CHK/INF        |
        |-------------------------------------------------------|
 BUGP1: |            Temp Storage for BUGSTO Routine            |
        |-------------------------------------------------------|
 BUGP2: |            Temp Storage for BUGSTO Routine            |
        |-------------------------------------------------------|
 BUGP3: |            Temp Storage for BUGSTO Routine            |
        |-------------------------------------------------------|
 BUGTMS:|               Time to Store Next BUGTIM               |
        |         (Length of Interval Is BUGINT = 5 min)        |
        |-------------------------------------------------------|
 BUGTIM:|          ASCII Time & Data Stored for BUGHLT          |
        +-------------------------------------------------------+
                                                     Page 10


                            CDB

Channel Data Block.  This table, one per  channel,  contains
channel  dependent  instructions  and  data, pointers to the
units (i.e.  UDBs) belonging to the channel and  information
about   the   currently   active  unit.   When  the  channel
interrupts,  control  passes  (via  a  JSP  instruction)  to
CDBINT.   The  CDB  address  is  stored  in  AC, P1, and the
principal analysis routine, PHYINT, is called.

Defined in:  PHYPAR

Referenced by:  PHYSIO, PHYH2, PHYM2, PHYP4

                                 Format

        +-------------------------------------------------------+
CDBINT  |                       0(2-word PC stored on interrupt)|
        |-------------------------------------------------------|
    -5  |                       0                               |
        |-------------------------------------------------------|
    -4  |               (Flags) 0                               |
        |-------------------------------------------------------|
    -3  |                       0,, .+1                         |
        |-------------------------------------------------------|
    -2  |                 MOVEM P1, .+2+CDBSVQ                  |
        |-------------------------------------------------------|
    -1  |                   JSP P1, PHYINT                      |
        |-------------------------------------------------------|
CDBSTS=0|         Status and Configuration Information          |
        |-------------------------------------------------------|
CDBMBW=1|        Memory Bandwidth Scheduling Information        |
        |-------------------------------------------------------|
CDBODT  |        Overdue Timer when Data Transfer Active        |
        |-------------------------------------------------------|
CDBICP  |           EXEC Virtual Adrs (EPT Adrs) of             |
        |          Interrupt Vector,, Data Logout Area          |
        |-------------------------------------------------------|
CDBIUN  |          Initial AOBJN Pointer to  UDB Table          |
        |-------------------------------------------------------|
CDBCUN  |          Current AOBJN Pointer to UDB Table           |
        |-------------------------------------------------------|
CDBDSP  |  Unit Utilities Dispatch  |    Main Entry Dispatch    |
        |                           |  (Channel Dispatch Table) |
        |-------------------------------------------------------|
CDBFCT  |              Fairness Count for Latency               |
        |-------------------------------------------------------|
CDBPAR  |             Channel Memory Parity Errors              |
        |-------------------------------------------------------|
CDBNXM  |                     Channel NXMs                      |
        |-------------------------------------------------------|
CDBXFR  |              Currently Transferring UDB               |
        |-------------------------------------------------------|
CDBCCL  \            Channel Command List (3 words)             \
        |-------------------------------------------------------|
                                                     Page 11


        |                                                       |
CDBUDB  |                  UDB Table (8 words)                  |
        \                                                       \
        |-------------------------------------------------------|
CDBSVQ  |        P1 Saved Here on Vector Interrupt Entry        |
        |-------------------------------------------------------|
CDBJEN  |                    BLT 17, 17   (Interrupt Dismiss)   |
        |-------------------------------------------------------|
        |                  DATA0 RH, CDBRST                     |
        |-------------------------------------------------------|
        |                   XJEN CDBINT(P1)                     |
        |-------------------------------------------------------|
CDBRST  |                Location Used by CDBJEN                |
        |-------------------------------------------------------|
CDBCNI  |          Channel CONI at Start of Interrupt           |
        |-------------------------------------------------------|
CDBONR  |          Fork Who Has Channel in Maint. Mode          |
        |-------------------------------------------------------|
CDBADR  |         Number of This Channel (CHNTAB index)         |
        |-------------------------------------------------------|
CDBCS0  |               Channel Status 0 at Error               |
        |-------------------------------------------------------|
CDBCS1  |                   Channel Status 1                    |
        |-------------------------------------------------------|
CDBCS2  |                   Channel Status 2                    |
        |-------------------------------------------------------|
CDBCC1  |                       First CCW                       |
        |-------------------------------------------------------|
CDBCC2  |                      Second CCW                       |
        |-------------------------------------------------------|
CDBOVR  |                  Number of Overruns                   |
        |-------------------------------------------------------|
CDBICR  |           Initial STCR When Device Started            |
        |-------------------------------------------------------|
CDBCL2  \             Alternate CCW List (3 words)              \
        |-------------------------------------------------------|
CDBDDP  \             CDB Device Dependent Block                \
        \                                                       \
        \                                                       \
        |                                                       |
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                                                     Page 12






         0 1 2 3 4 5 6                      25 26 28 9 0 31    35
        +-------------------------------------------------------+
 CDBSTS | | | | | | |                         | PIA |   | TYPE  |
        +-------------------------------------------------------+


Symbol     Bits         Content

CS.OFL       0          Offline
CS.AC1       1          Primary command active
CS.AC2       2          Secondary command active
CS.MAI       3          Channel is in maint. mode
CS.MRQ       4          Maint. mode requested for a unit
CS.ERC       5          Error recovery in progress
CS.STK       6          Channel Support Command Stacking
CS.ACL       7          Alternate CCW List is Current
           26-28        PIA field
           31-35        Channel type field


CDBDSP
    See Tables, UDS and CDS


CDBDDP
    CDB Device Dependent Block for the RH20 Controller


                +-------------------------------------+
  CDBDDP=RH2CNI |            CONI RH2, TI             |
                |-------------------------------------|
                |            CONO RH2, T2             |
                |-------------------------------------|
                |            DATAI RH2, T1            |
                |-------------------------------------|
                |            DATAO RH2, T2            |
                +-------------------------------------+
                                                     Page 13


    CDB Device Dependent Block for the RH11 Controller

                +-------------------------------------+
  CDBDDP=RC1CS1 |          Control Status 1           |
                |-------------------------------------|
         RC1DS  |        Drive Status Register        |
                |-------------------------------------|
         RC1ER1 |          Error Register 1           |
                |-------------------------------------|
         RC1MR  |        Maintenance Register         |
                |-------------------------------------|
         RC1AS  |     Attention Summary Register      |
                |-------------------------------------|
         RC1DA  |      Desired Address Register       |
                |-------------------------------------|
         RC1DT  |        Driver Type Register         |
                |-------------------------------------|
         RC1LA  |         Look Ahead Register         |
                |-------------------------------------|
         RC1SN  |       Serial Number Register        |
                |-------------------------------------|
         RC1OF  |           Offset Register           |
                |-------------------------------------|
         RC1DC  |      Desired Cylinder Register      |
                |-------------------------------------|
         RC1CA  |      Current Cylinder Register      |
                |-------------------------------------| 
         RC1ER2 |          Error Register 2           |
                |-------------------------------------|
         RC1ER3 |          Error Register 3           |
                |-------------------------------------|
         RC1EC1 |           ECC Register 1            |
                |-------------------------------------|
         RC1EC2 |           ECC Register 2            |
                |-------------------------------------|
         RC1WC  |         Word Count Register         |
                |-------------------------------------|
         RC1BA  |      Current Address Register       | 
                |-------------------------------------|
         RC1CS2 |    Control and Status Register 2    |
                |-------------------------------------|
         UBADSW |   Unibus Status Register Address    |
                |-------------------------------------|
         UBBASA |     Unibus Bus Addr. Base Addr.     |
                +-------------------------------------+
                                                     Page 14


                      CDR-STORAGE-AREA

Card Readers (Physical) Storage Area.  Most entries are CDRN
words  long  where CDRN equals the number of card readers on
the system.

Defined in:  STG

Referenced by:  CDRSRV
        



                                Format

                                                                  
        +-----------------------------------------------+ / \
        \                                               \ CDEN
CDRCT1: \                 Buffer Count                  \ \ /
        |-----------------------------------------------| / \
CDRCKT: \            Word for Scheduler Test            \ CDRN
        |-----------------------------------------------| \ /
        \                                               \ / \
CDRSTS: \                  Status Word                  \*CDRN
        |-----------------------------------------------| \ /
        \                                               \ / \
CDRST1: \              Second Status Word               \*CDRN
        |-----------------------------------------------| \ /
        \                                               \ / \
CDRST2: \               Third Status Word               \*CDRN
        |-----------------------------------------------| \ /
        \                                               \ / \
CARDCT: \              Count of Cards Read              \ CDRN
        |-----------------------------------------------| \ /
        \                                               \ / \
CARDER: \          Number of "Hardware" Errors          \ CDRN
        |-----------------------------------------------| \ /
CDRLCK: |                 CDR Lock Word                 |
        |-----------------------------------------------|
CDRCNT: |             Count of CDRs Opened              |
        |-----------------------------------------------|      --
        \                                               \ / \   |
CDUBAD: \            Address of UBA Window              \ CDRN  |
        |-----------------------------------------------| \ /   |
        \                                               \ / \   |
CD11A:  \          Address of UBA-11 Address            \ CDRN  |
        |-----------------------------------------------\ \ /   |
        \                                               \ / \  KS10
CDERBF: \          Error Status for Cardreader          \ CDRN ONLY
        \                                               \ *16   |
        |-----------------------------------------------| \ /   |
        \                                               \ / \   |
CDUNIT: \           Unit Number of Cardreader           \ CDRN  |
        +-----------------------------------------------+ \ /  --
                                                     Page 15



        The Non-resident area contains:

        +-----------------------------------------------+ / \
        |                                               |  |
CDRBUF: \               Card Reader Buffer              \ 1 Page
        |                                               |  |
        +-----------------------------------------------+ \ /



       0                          17 8 9 20                      35
      +------------------------------------------------------------+
      | CDFRK                       | | |  CDERR                   |
CDRSTS|          Owning Fork        | | |      Last Error Condition|
      +------------------------------------------------------------+

                Bits        Pointer     Content

                 0-17       CDFRK       Owning fork
                  18        CDOL        If one, cards in reader
                  19        CDBLK       Waiting for a card
                20-35       CDERR       Last error condition

       0 1 2 3 4 5    11 2 3 4 5 6 17 18                         35
      +------------------------------------------------------------+
      | | | | | |       | | | | | | |CDWRD                         |
CDRST1| | | | | |       | | | | | | | Current Internal Storage Word|
      +------------------------------------------------------------+

                Bits        Pointer     Content

                  0         CDAII       CDR opened in ASCII
                  1         CDATN       CDR needs attention
                  2         CDMSG       Suppress system messages
                  3         CDOPN       CDR is open
                  4         CDER        Error in this CDR
                 12         CDCNT       Count of bytes now in buffer
                 13         CDEOF       EOF button was pushed
                 14         CDBUF       Buffer for process level
                 15         CDPIR       Process needs interrupt
                 16         CDBFI       Buffer for PI level
                 17         CDDON       If one, doing a buffer by process
               18-35        CDWRD       Current internal storage word
                                                     Page 16


       0 1 2 3 4 5 6 7     11 12       17 8 9 20                 35
      +------------------------------------------------------------+
      | | | | | |   |        |           |   |CDSST                |
CDRST2| | | | | |   |        |   CDPSI   |   | Software Status Word|
      +------------------------------------------------------------+

Symbol          Bits        Pointer     Content

CD%SHA            0         CDSHA       "Status has arrived" flag
                  1         CDMWS       MTOPR is waiting for status to
                                         arrive
CD%RLD            2         CDRLD       Front end has reloaded
                  3         CDOFI       Offline interrupt is pending
                  4         CDEFI       End of file interrupt 
                                        already given
                 5-6        CDRTYP      Type of card reader
                  7         CDEXST      Existance of reader
                12-17       CDPSI       PSI chan. no. for on-line
                                         transitions
                20-35       CDSST       Software status word


                                        Symbol  Bits   Content


                                        .DVFFE   28    Device has a
                                                        fatal, unre-
                                                        coverable error
                                        .DVFLG   29    Error logging
                                                        info. follows
                                        .DVFEF   30    EOF
                                        .DVFIP   31    I/O in progress
                                        .DVFSE   32    Software cond.
                                        .DVFHE   33    Hardware error
                                        .DVFOL   34    Offline
                                        .DVFNX   35    Nonexistent device
                                                     Page 17


                            CDS

Channel Dispatch Service Routine Table.  This table contains
vectored  addresses  to  channel dependent functions, and is
given  in  its  generalized  form.   The  specific   channel
dispatch  table for the RH20 begins at RH2DSP in PHYH2.  See
PHYPAR for definitions of arguments given  and  returned  on
calls to these channel routines.

Defined in:  PHYPAR

Referenced by:  PHYH2, PHYM2, PHYP4, PHYSIO, STG

                                Format

         +-------------------------------------------------------+
CDSINI=0 |          Initialize and Build Data Structure          |
         |-------------------------------------------------------|
CDSSTK=1 |   Stack Second Channel Command, Skip if OK            |
         |-------------------------------------------------------|
CDSSIO=2 |       Start I/O on IORB (skip if started O.K.)        |
         |-------------------------------------------------------|
CDSPOS=3 |     Do Positioning to Idle Unit (skips if O.K.)       |
         |-------------------------------------------------------|
CDSLTM=4 |      Return Latency and Best Request (i.e. best IORB) |
         |-------------------------------------------------------|
CDSINT=5 |                    Interrupt Entry                    |
         |-------------------------------------------------------|
CDSCCW=6 |               Generate Single CCW Entry               |
         |-------------------------------------------------------|
CDSHNG=7 |                      Hung Reset                       |
         |-------------------------------------------------------|
CDSRST=10|       On Restart, Reset Channel and All Devices       |
         |-------------------------------------------------------|
CDSCHK=11|            Periodic Check Entry, PIA, etc.            |
         +-------------------------------------------------------+
                                                     Page 18


                           CHNTAB

Channel Table, indexed by channel number,  contains  channel
data block (CDB) pointers.

Defined in:  STG

Referenced by:  DIAG, DSKALC, PHYH11, PHYH2, PHYSIO

Index:  Channel Number

                                Format

        +-----------------------------------------------+  / \
CHNTAB: |                  CDB Pointer                  |   |
        |-----------------------------------------------|   |
        |                       .                       |
        |                       .                       | CHNN
        |                       .                       |
        |                       .                       |   |
        \                       .                       \   |
        +-----------------------------------------------+  \ /
                                                     Page 19


                  CLASS-SCHEDULER-STORAGE

This storage is used by the class scheduling algorithms.

Defined in:  STG

Referenced by:  SCHED

Index:  A number of the sections are indexed by either class
        (sections   of  length  MAXCLS)  or  by  job  number
        (sections of length NJOBS).

                                 Format

        +-------------------------------------------------------+
MJBUSE: |                  Highest job in use                   |
        +-------------------------------------------------------+
RDRTIM: |                Time to do next reorder                |
        +-------------------------------------------------------+
UTLTIM: |              Time to compute utilization              |
        +-------------------------------------------------------+
UTLINT: |         Interval to compute next utilization          |
        +-------------------------------------------------------+
OLDSLD: |                  Previous sold time                   |
        +-------------------------------------------------------+
CLASSF: |         If non-zero, doing classy scheduling          |
        +-------------------------------------------------------+
CLSCTL: |                  Class control word                   | *
        +-------------------------------------------------------+
CLSUTL: |                                                       | /\
        |                   Class utilization                   | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+
JOBCLS: |                                                       | /\
        |                     Class per job                     | NJOBS
        \                           .                           \ \/
        +-------------------------------------------------------+
JOBUTL: |                                                       | /\
        |                    Job utilization                    | NJOBS
        \                           .                           \ \/
        +-------------------------------------------------------+
JOBIRT: |                                                       | /\
        |                Job incremental runtime                | NJOBS
        \                           .                           \ \/
        +-------------------------------------------------------+
JOBDST: |                                                       | /\
        |                     Job distance                      | NJOBS
        \                                                       \ \/
        +-------------------------------------------------------+
CLSSHR: |                                                       | /\
        |                      Class share                      | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+
WA:     |                                                       | /\
        |              Windfall allocation (or -1)              | MAXCLS
                                                     Page 20


        \                           .                           \ \/
        +-------------------------------------------------------+
CLSSHI: |                                                       | /\
        |                   Share per member                    | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+
CLSCNT: | CLGLC                     |                           | / \
        |    Count of processes     |                           | MAXCLS
        |    on GOLST per class     |                           |  |
        \                           .                           \ \ /
        +-------------------------------------------------------+
CLSDST: |                                                       | /\
        |                    Class distance                     | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+
CLSSUM: |                                                       | /\
        |             Integral of NRUN for classes              | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+
CLSIRT: |                                                       | /\
        |               Class incremental runtime               | MAXCLS
        \                           .                           \ \/
        +-------------------------------------------------------+

         0 1          9 10         18 19 20     25 26         36
        +-------------------------------------------------------+
CLSCTL  | |   CLSDF    |    CLSBT    |  |  CLSKV  |             |
entry   +-------------------------------------------------------+

                  Bits      Pointer     Content

                   0        CLSBD       BATCH jobs to dregs queue
                  1-9       CLSDF       Default class
                 10-18      CLSBT       Batch class
                  19        CLSAC       If on, class by accounts
                 20-25      CLSKV       Current knob value
                                                     Page 21


                            CST0

Core Status Table 0 (sometimes referred to  as  CST).   Each
entry  in  this  table, is principally defined by the pager.
If the page is in use, the entry contains the age stamp  for
the page, which processes have referenced it and whether the
page has been modified.  The age stamp field is used to show
the page's state if it is not assigned to a process.

Defined in:  STG

Referenced by:  APRSRV, DIAG, DSKALC, PAGEM

Index:  Physical page number

                                Format

        +-------------------------------------------------------+
        |  CSTAGE     |                                       | |   / \
   CST0:|     Age     |         Process Use Register          |M|    |
        |-------------------------------------------------------|    |
        |                          or                           |    |
        |-------------------------------------------------------|    |
        |  CSTAGE     | XGAGE  |  CFXRD                    |    |    |
        | Page State  |        |          Fork #           |    |    |
        |-------------------------------------------------------|    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |
        |                           .                           | MAXCOR
        |                           .                           |  
        \                           .                           \    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |   \ /
        +-------------------------------------------------------+
                                                     Page 22


       Symbol     Bits     Pointer      Content

                  0-8      CSTAGE       If page in use, contents of 
                                        pager age register ( >= 100 )
                                        at last age register reload

                  9-14     XGAGE        Age at last XGC (low bits only)

       CORMB       35                   This is the "modified" bit which 
                                        is set by the pager on any write
                                        reference. This bit will be 1 if
                                        the page has been written since
                                        the last operation.

       AGEMSK     0-8      CSTAGE       If page not in use, this field 
                                        indicates (right-justified) the
                                        page state as follows:

                                        PSRPQ = 0  On replaceable queue
                                        PSDEL = 1  To be put on replace 
                                                    able queue
                                        PSRDN = 2  Read completed
                                        PSWIP = 4  Write in progress
                                        PSRIP = 6  Read in progress
                                        PSSPQ = 7  Page on special memory 
                                                    queue
                                        PSASN = 10 Page assign to process 
                                                    if age field >=
                                                    PSASN.
                                                    (The age field should 
                                                     always be strictly
                                                     greater than 10 as
                                                     it is initialized
                                                     to 100 and increases
                                                     in value as process
                                                     runs.)

                 15-32     CFXRD        Number of fork which initiated
                                        read if page not in use
                                        (i.e. age field < 10).

    PSTFLD       33-34     CSTPST       Special page state

                                        PSTAVL=.MCPSA=0  Available for
                                                          RPLQ when freed
                                        PSTSPM=.MCPSS=1  Place on SPMQ
                                                          when freed
                                        PSTOFL=.MCPSO=2  Offline-action
                                                          as PSTSPM
                                        PSTERR=.MCPSE=3  Offline due to
                                                          error action as
                                                          PSTSPM
                                                     Page 23


                            CST1

Core Status Table 1.  This table is referenced only  by  the
software  and  is  parallel  to  CST0.  It contains the lock
count which indicates the number of system events  requiring
the  page be locked in core (i.e., page table contains other
core addresses)  and  the  backup  address  (next  level  of
storage) for each page in core (1000000 if unassigned).

Defined in:  STG

Referenced by:  PAGEM, PHYSIO, SCHED

Index:  Physical page number

                                Format

        +-----------------------------------------------+
        |  PLKMSK   |  |                                |
CST1:   |Lock Count |  |        Backup Address          |   / \
        |-----------------------------------------------|    |
        |                       .                       |    |
        |                       .                       |    |
        |                       .                       |    |
        |                       .                       |    
        |                       .                       |  MAXCOR
        |                       .                       |       
        |                       .                       |    |
        |                       .                       |    |
        |                       .                       |    |
        |                       .                       |    |
        \                       .                       \   \ /
        +-----------------------------------------------+

   Symbol       Bits      Pointer     Content

    PLKV        0-11      PLKMSK      Lock count field-if non-zero,
                                      the page will not be 
                                      considered for swapping
                 11                   Page lack value in CST1
               14-35                  Backup address
                                                     Page 24


                            CST2

Core Status  Table  2  (Home  Map  Location).   This  table,
indexed  by  physical page number, is referenced only by the
software and is parallel to CST0.  It contains the home  map
location  for  the page (i.e., the page table which contains
the core address pointing to the page).

If the left half is 0, the home map is the SPT and the right
half contains the SPT index.  If the left half is not 0, the
home map is a page table or index block, where  PTN  is  the
SPT  index of that map and PN is the page number within that
map.

(See the SPT and SPTH table descriptions.)

Defined in:  STG

Referenced in:  PAGEM, PHYSIO

Index:  Physical page number

                                Format

        +-------------------------------------------------------+
CST2:   |            PTN            |            PN             |  / \
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |-------------------------------------------------------|   |
        |             0             |           SPTN            |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | MAXCOR
        |                           .                           |  
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+


                            NOTE

               The SPTN/PTN value  (both  SPT
               indexes)  is  used  to specify
               the kind of  page  represented
               in   the   CST2   table.   For
               example, if the  SPTN  in  the
               second format above is greater
               than or equal to NOFN  (length
               of the OFN area), the process'
                                                     Page 25


               page is a file page pointed to
               by  a  shared  pointer or fork
               overhead   page.     Otherwise
               (i.e.,   SPTN<NOFN),  it's  an
               index block  page.*  Likewise,
               if  the PTN value in the first
               format above is  greater  than
               or  equal to NOFN, the page is
               a private process page  (i.e.,
               pointed to by a direct pointer
               from   the   process'    map).
               Otherwise (i.e., PTN<NOFN), it
               is  a   process'   file   page
               pointed   to  by  an  indirect
               pointer through the file's own
               page table, the index block.*

               * In both of these cases  when
               an  index  block  is  involved
               (i.e., SPTN/PTN< NOFN), it  is
               common  to find in the monitor
               listings     the      symbolic
               notation,    OFN,    replacing
               SPTN/PTN.
                                                     Page 26


                            CST3

Core Status Table 3.  This table, indexed by  physical  core
page  number,  is  referenced  only  by  the software and is
parallel to CST0.  An entry in this  table  is  used  for  a
variety  of purposes, generally as a list pointer for groups
of pages on various queues.  

For example, when on the replaceable queue,  the  left  half
and  right  half contain backward and forward list pointers,
respectively.  When on a swapping device  queue,  the  right
half  contains  a  forward list pointer and B0 is 1 if write
and 0 if read.  Other queues threaded through this table are
the deletion and special memory queues.

When the page is in use (not linked on one of  the  queues),
it contains the local disk address for PHYSIO and the fork  
assigned to the page.

Defined in:  STG

Referenced by:  PAGEM, PHYSIO, SCHED

Index:  Physical page number

                                Format

        +-------------------------------------------------------+
   CST3:|   Backward List Pointer   |   Forward List Pointer    |   / \
        |-------------------------------------------------------|    |
        |                          or                           |    |
        |-------------------------------------------------------|    |
        | |                         |   Forward List Pointer    |    |
        |-------------------------------------------------------|    |
        |                          or                           |    |
        |-------------------------------------------------------|    |
        |      |  CSTOFK      |  CSTLDA                         |*   |
        |Flags |    Fork #    |       Local Disk Address        |
        |-------------------------------------------------------| MAXCOR
        |                           .                           |  
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        |                           .                           |    |
        \                           .                           \   \ /
        +-------------------------------------------------------+
                                                     Page 27



         0 1 2 3                    14 15                            35
        +--------------------------------------------------------------+
        | | | |  CSTOFK               |  CSTLDA                        |
        | | | |        Fork #         |            Local Disk Address  |
        +--------------------------------------------------------------+


                Symbol    Bits    Pointer   Content

                DWRBIT     0                Set if write in progress.
                                            The bit is cleared by the
                                            swapper when the write
                                            completes.

                SWPERR     1                Set if an unrecoverable
                                            error occurred when this
                                            page read in from disk/drum

                DSKSWB     2                Swap to disk requested by 
                                            DDMP (periodic routine that
                                            trickles file pages to the
                                            disk) or by monitor when
                                            certain monitor calls are
                                            issued, e.g., CLOSF

                         3-14    CSTOFK     Process to which this page
                                            is assigned (7777 is not
                                            assigned).

                        15-35    CSTLDA     Local disk address for
                                            PHYSIO
                                                     Page 28


                            CST5

Core Status Table 5.  This table, indexed by  physical  core
page  number,  is  referenced  only  by  the software and is
parallel to CST0.  It is a table of short IORBs.   (See  the
IORB table description for format of the IRBSTS entry.)

Defined in:  STG

Referenced by:  PHYH2J, PHYSIO

Index:  Physical page number


                                Format


        +-------------------------------------------------------+
CST5:   |           Flags           | Next Disk IORB(short/long)|  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | MAXCOR
        |                           .                           | 
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 29


                          DEV`DTB

Device Dispatch Table.  Each device  has  its  own  dispatch
table that conforms to the format described below.  An error
return dispatch address is placed in those words which  have
no corresponding device function.  The naming convention for
these tables is the device name concatenated with DTB  (i.e.
MTADTB, DSKDTB, TTYDTB, etc.)

Defined in:  PROLOG

Referenced by:  

                                Format

         +-------------------------------------------------------+
DLUKD=0  |                    Directory Setup                    |
         |-------------------------------------------------------|
NLUKD=1  |                      Name Lookup                      |
         |-------------------------------------------------------|
ELUKD=2  |                   Extension Lookup                    |
         |-------------------------------------------------------|
VLUKD=3  |                    Version Lookup                     |
         |-------------------------------------------------------|
PLUKD=4  |                 Protection Insertion                  |
         |-------------------------------------------------------|
ALUKD=5  |                   Account Insertion                   |
         |-------------------------------------------------------|
SLUKD=6  |                 Status Modification                   |
         |-------------------------------------------------------|
OPEND=7  |                       Open File                       |
         |-------------------------------------------------------|
BIND=10  |                 Sequential Byte Input                 |
         |-------------------------------------------------------|
BOUTD=11 |                Sequential Byte Output                 |
         |-------------------------------------------------------|
CLOSD=12 |                      Close File                       |
         |-------------------------------------------------------|
REND=13  |                    Rename File                        |
         |-------------------------------------------------------|
                                                     Page 30


DELD=14  |                      Delete File                      |
         |-------------------------------------------------------|
DMPID=15 |                    Dump Mode Input                    |
         |-------------------------------------------------------|
DMPOD=16 |                   Dump Mode Output                    |
         |-------------------------------------------------------|
MNTD=17  |                         Mount                         |
         |-------------------------------------------------------|
DSMD=20  |                       Dismount                        |
         |-------------------------------------------------------|
INDD=21  |                Initialize a Directory                 |
         |-------------------------------------------------------|
MTPD=22  |                   MTAPE Operations                    |
         |-------------------------------------------------------|
GDSTD=23 |                   Get Device Status                   |
         |-------------------------------------------------------|
SDSTD=24 |                   Set Device Status                   |
         |-------------------------------------------------------|
RECOUT=25|               Force Record Out (SOUTR)                |
         |-------------------------------------------------------|
RFTADD=26|                Read File Time and Date                |
         |-------------------------------------------------------|
SFTADD=27|                Set File Time and Date                 |
         |-------------------------------------------------------|
JFNID=30 |                 Set JFN for Input                     |
         |-------------------------------------------------------|
JFNOD=31 |                Set JFN for Output                     |
         |-------------------------------------------------------|
ATRD=32  |                  Check Attribute                      |
         +-------------------------------------------------------+
                                                     Page 31


                           DEVCH1

Device  Characteristics  Table  1.   This  table,   contains
another  word  of  information about each device unit in the
system and is initialized from the INIDVT  table  at  system
start up time.

Defined in:  STG, MONSYM

Referenced by:  DEVICE, DSKALC, FILINI, FUTILI, GTJFN,
                JSYSA, JSYSF, MEXEC, MSTR

                                Format

        +-------------------------------------------------------+
DEVCH1: |            Device Characteristics (word 2)            | / \
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |
        |                           .                           |NDEV
        |                           .                           |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \ \ /
        +-------------------------------------------------------+ 


                Symbol          Bit             Content

                D1%%SPL          0              Device is spooled
                D1%%ALC          1              Device is under control
                                                 of allocator
                D1%%VVL          2              Volume valid
                D1%%NIU          3              Device slot not is use
                D1%%INI          4              Device is being initialized
                                                 currently for structures
                                                 only)
                                                     Page 32


                           DEVCH2

Device Characteristcs Table 2.  This  table  contains  spool
directory information and is parallel to the DEVCH1 table.  

Defined in:  STG

Referenced by:  DISC, JSYSA

                                Format

        +-------------------------------------------------------+
DEVCH2: |          Directory Number of Spool Directory          | / \
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |
        |                           .                           |NDEV
        |                           .                           |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \ \ /
        +-------------------------------------------------------+
                                                     Page 33


                           DEVCHR

Device Characteristics Table.  This table  contains  indexed
information  about  each device unit and is initialized from
the INIDVT table at system startup time.  See  INIDVT  table
for bit definitions.

Defined in:  STG

Referenced by:  DEVICE, DISC, FILMSC, GTJFN, JSYSA, JSYSF,
                MEXEC, TTYSRV

                                Format

                    8  9          17 18                       35
        +-------------------------------------------------------+
DEVCHR: |   CHAR1*   |    TYPE      |           MODES           |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NDEV
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+


                *CHAR1
                    Bit 5 can take on another meaning (i.e., DV%OPN=1B5;
                    File Open on Device) than the one described in INIDVT.

                Note:  A resident word, DEVLCK (Free is -1), is used to
                       lock the data base in the DEVXXX Tables when they
                       are being manipulated.
                                                     Page 34


                           DEVDSP

Device Dispatch Table Addresses.  This  table  contains  the
device   dispatch   table   for  each  device  unit  and  is
initialized from the INIDVT table at system startup time.

Defined in:  STG

Referenced by:  DEVICE, JSYSA, JSYSF

                                Format

        +-------------------------------------------------------+
DEVDSP: |  Device Type Index        |  Dispatch Table Address   |  / \
        |   (Not Referenced)        |                           |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NDEV
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 35


                           DEVNAM

Device Name Table.  This table contains  the  SIXBIT  device
name  for  each  device  unit.   The  generic device name is
obtained from INIDVT, modified to include  unit  number  (if
device  has  units) and stored in this table at system start
up time.

Defined in:  STG

Referenced by:  DEVICE, FILINI, GTJFN, IPCF, JSYSA, MEXEC,
                MSTR

                                Format

        +-------------------------------------------------------+
DEVNAM: |                    SIXBIT / Name /                    |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NDEV
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 36


                           DEVUNT

Device Unit Table.  This table,  contains  infomation  about
the  job  associated with a unit, where the unit information
in DEVUNT is built at system startup utilizing data from the
INIDVT table.

Defined in:  STG

Referenced by:  DEVICE, DSKALC, FILINI, FILMSC, JSYSA, JSYSF
                MEXEC, MSTR, TAPE, TTYSRV

                                Format

        +-------------------------------------------------------+
DEVUNT: |Assigner's Job#/Dev Free(-1)|Unit # or No Unit Dev(-1) | / \
        |                            | or being controlled by   |  |
        |                            | the allocator (-2)       |  |
        |-------------------------------------------------------|  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |
        |                            .                          |NDEV
        |                            .                          |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        |                            .                          |  |
        \                            .                          \ \ /
        +-------------------------------------------------------+
                                                     Page 37


                         DIRECTORY

Directory Format.   The  following  illustrations  show  the
format of a TOPS-20 directory.

Defined:  PROLOG

Referenced by:  DIRECT, DISC, DSKALL
        
                        Overview of a Directory

        +-------------------------------------------------------+
        |                                                       |
        |                        Page 0                         |
        |                                                       |
        |-------------------------------------------------------|
        |                                                       |
        |                        Page 1                         |
        |                                                       |
        |-------------------------------------------------------|
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |-------------------------------------------------------|
        |                                                       |
        |                        Page n                         |
        |                                                       |
        |-------------------------------------------------------|
        |                                                       |
        |                                                       |
        |                     Symbol Table                      |
        |                                                       |
        |                                                       |
        |-------------------------------------------------------|
        |                                                       |
        |                                                       |
        |           Reserved for Directory Expansion            |
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                                                     Page 38



                        First Page of a Directory
        

         0                        17 18    23 24
        +-------------------------------------------------------+
        |  DRTYP                    | DRVER  |  DRHLN           |
        | Block Type TYDIR (400300) | Ver. # | Length of Header |
        |-------------------------------------------------------|
        |  DRRPN                    |  DRNUM                    |
        |  Relative Page # in DIR   |     Directory Number      |
        |-------------------------------------------------------|
        |  DRFFB                                                |
.DRFFB=2|              Pointer to First Free Block              |
        |-------------------------------------------------------|
        |  DRSBT                                                |
        |           Address of Bottom of Symbol Table           |
        |-------------------------------------------------------|
        |  DRSTP                                                |
        |            Address of Top of Symbol Table             |
        |-------------------------------------------------------|
        |  DRFTP                                                |
        |   Address of Last Used Word+1 for Strings and FDBs    |
        |-------------------------------------------------------|
        |  DRFBT                                                |
        |               Pointer to Free Bit Table               |
        |-------------------------------------------------------|
        |  DRDPW                                                |
        |                Default File Protection                |
        |-------------------------------------------------------|
        |  DRPRT                                                |*
        |             Default Directory Protection              |
        |-------------------------------------------------------|
        |  DRDBK                                                |
        |                 Backup Specification                  |
        |-------------------------------------------------------|
        |  DRLIQ                                                |
        |                    Logged In Quota                    |
        |-------------------------------------------------------|
        |  DRLOQ                                                |
        |                   Logged Out Quota                    |
        |-------------------------------------------------------|
        |  DRDCA                                                |
        |             Current Directory Allocation              |
        |-------------------------------------------------------|
        |  DRNAM                                                |
        |           Pointer to Directory Name String            |
        |-------------------------------------------------------|
        |  DRPSW                                                |
        |              Pointer to Password String               |
        |-------------------------------------------------------|
        |  DRPRV                                                |
        |                    Privilege Bits                     |
        |-------------------------------------------------------|
        |  DRMOD                                                |
                                                     Page 39


        |                       Mode Bits                       |
        |-------------------------------------------------------|
        |  DRDAT                                                |
        |              Date and Time of Last LOGIN              |
        |-------------------------------------------------------|
        |  DRUGP                                                |
        |              Pointer to User Group List               |
        |-------------------------------------------------------|
        |  DRDGP                                                |
        |            Pointer to Directory Group List            |
        |-------------------------------------------------------|
        |  DRUDT                                                |
        |       Date and Time of Last Update to Directory       |
        |-------------------------------------------------------|
        |  DRSDM                   |  DRSDC                     |
        |  Max # of Subdirectories |  Count of Subdirectories   |
        |-------------------------------------------------------|
        |  DRCUG                                                |
        |      CRDIR allowed specifying these User Groups       |
        |-------------------------------------------------------|
        |  DRACT                                                |
        |            Pointer to Dir. Default Account            |
        |-------------------------------------------------------|
        |  DRDNE                                                |
        |         Default online expiration date/interval       |
        |-------------------------------------------------------|
        |  DRDFE                                                |
        |        Default offline expiration date/interval       |
        |-------------------------------------------------------|
        |                                                       |
        |                    Spare Words                        |
        |                                                       |
        |                                                       |
        \                                                       \
        |-------------------------------------------------------|
        |                                                       |
        |            Free Space for Strings and FDBs            |
        |                                                       |
        \                                                       \
        +-------------------------------------------------------+
                                                     Page 40


                                      18      23 24     29 30     35
        +-----------------------------------------------------------+
 DRPRT  |                            |   DRPOW  |  DRPGP  |  DRPWL  | 
        +-----------------------------------------------------------+


               Bits       Pointer      Content

              18-23       DRPOW        Owner field
              24-29       DRPGP        Group field
              30-35       DRPWL        World field


                     General format for all blocks

       0                        17 18       23 24              35
      +----------------------------------------------------------+
      | BLKTYP                    | BLKVER    | BLKLEN           |
      |    Type code              |   Ver. #  |   Length         |
      +----------------------------------------------------------+

               Possible type codes are:

                  .TYNAM = 400001
                  .TYEXT = 400002
                  .TYACT = 400003
                  .TYUNS = 400004
                  .TYFDB = 400100
                  .TYLAC = 400200
                  .TYDIR = 400300
                  .TYSYM = 400400
                  .TYFRE = 400500
                  .TYFBT = 400600
                  .TYGDB = 400700
                                                     Page 41


                        Subsequent Directory Pages
                
                
                
                
        +-------------------------------------------------------+
        |  DRTYP                    | DRVER  |  DRHLN           |
        |    .TYDIR (400300)        | Ver. # | Length of Header |
        |-------------------------------------------------------|
        |  DRRPN                    |  DRNUM                    |
        |  Relative Page # in DIR   |     Directory Number      |
        |-------------------------------------------------------|
        |  DRFFB                                                |
        |              Pointer to First Free Block              |
        |-------------------------------------------------------|
        |                                                       |
        |                                                       |
        |            Free Space for Strings and FDBs            |
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                

                
                


                              Symbol Table
                
                
                
        |-------------------------------------------------------|
        |  SYMTY                    |        |  SYMDN           |
        |     .TYSYM (400400)       |        |Dir. # of Sym.Tbl.|
        |-------------------------------------------------------|
        |                          -1                           |
        |-------------------------------------------------------|
        |SYMET|  SYMAD                                          |   \
        |Type |                 Address of FDB                  |    \
        |-------------------------------------------------------|     >
        |  SYMVL                                                |    /
        |         First 5 Characters of Name, Account or User   |   /
        |         Name for last writer/author                   |
        |-------------------------------------------------------|
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |-------------------------------------------------------|   \
        |                                                       |    \
        |-------------------------------------------------------|     >
                                                     Page 42


        |                                                       |    /
        +-------------------------------------------------------+   /
                                

         0 1 2 3                                                   35
        +------------------------------------------------------------+
        |     |                                                      |
        |Type |                    Address of FDB                    |
        +------------------------------------------------------------+


                Bits    Pointer         Content

                0-2     SYMET           Entry Type
                                             0 = .ETNAM     Name
                                             2 = .ETUNS     User Name
                                             4 = .ETACT     Account
                3-35    SYMAD           Address of FDB



        User Name String


       +-------------------------------------------------------+
       | UNTYP                    |        |  UNLEN            |
       |    .TYUNS (400004)       | Ver. # |  Length           |
       |-------------------------------------------------------|
       | UNSHR                    |                            |
       |            Share Count of User Name String            |
       |-------------------------------------------------------|
       | UNVAL                                                 |
       |                 ASCIZ User Name String                |
       +-------------------------------------------------------+
                                                     Page 43





        Name String


        +-------------------------------------------------------+
        | NMTYP                     |       | NMLEN             |
        |    .TYNAM (400001)        | Ver. #| Length            |
        |-------------------------------------------------------|
        | NMVAL                                                 |
        |            ASCIZ Name String (1st 5 characters)       |
        |                                                       |
        +-------------------------------------------------------+
                
                
                
                
                
        Extension String
                
                
        +-------------------------------------------------------+
        | EXTYPE                    |        |EXLEN             |
        |    .TYEXT (400002)        | Ver.#  |Length            |
        |-------------------------------------------------------|
        |                                                       |
        |                ASCIZ Extension String                 |
        |                                                       |
        +-------------------------------------------------------+

        Account String
                
                
        +-------------------------------------------------------+
        | ACTYP                     |        |ALLEN             |
        |    .TYACT (400003)        | Ver. # | Length           |
        |-------------------------------------------------------|
        | ACSHR                                                 |
        |                      Share Count                      |
        |-------------------------------------------------------|
        | ACVAL                                                 |
        |                 ASCIZ Account String                  |
        |                                                       |
        +-------------------------------------------------------+
                                                     Page 44



        File Descriptor Block (FDB)

        +-------------------------------------------------------+
        | FBTYP                     | FBVER  | FBLEN            |
        |    .TYFDB (400100)        | Ver. # |       Length     |
        |-------------------------------------------------------|
        |                                                       |
        |                                                       |
        \       See FDB Table for Details of this Block         \
        \                                                       \
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                
                
                
                
                
        Free Space
                
                
        +-------------------------------------------------------+
        | FRTYP                     | FRVER  | FRLEN            |
        |    .TYFRE (400500)        | Ver. # |      Length      |
        |-------------------------------------------------------|
        | FRNFB                                                 |
        |     Pointer to Next Free Block or 0 if at end         |
        |-------------------------------------------------------|
        |                                                       |
        |                                                       |
        \                Remainder of Free Block                \
        \                                                       \
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                
                                                     Page 45


                
                
        Free Storage Bit Table
                
                
        +-------------------------------------------------------+
        |                           |       |                   |
        |    .TYFBT (400600)        | Ver. #|  Length           |
        |-------------------------------------------------------|
        |                                                       |
        \     Bit Table Containing 1 Bit per Directory Page     \
        \                                                       \
        |                0 = No Room on the Page                |
        |             1 = There is Room on the Page             |
        +-------------------------------------------------------+
                

                
                
                
                
                
        Group List
                
                
        +-------------------------------------------------------+
        |                           |        |                  |
        |    .TYGDB (400700)        | Ver. # | Length           |
        |-------------------------------------------------------|
        |         Group #           |          Group #          |
        |-------------------------------------------------------|
        |          Group #          |             0             |
        +-------------------------------------------------------+
                                                     Page 46


                           DRMBBT

Drum Bit Table.  This bit table indicates which pages are in
use and which pages are available in the swapping area.

Defined in:  STG

Referenced by:  SWPALC

                                Format

        +-------------------------------------------------------+           / \
DRMBBT: \                                                       \  \         |
        \                                                       \Cylinder 0  |
        |                                                       |  /         |
        |-------------------------------------------------------|            |
        \                                                       \  \         |
        \                                                       \Cylinder 1  |
        |                                                       |  /         |
        |-------------------------------------------------------|            |
        |                           .                           |            |
        |                           .                           |            
        |                           .                           |          DRMMXB
        |                           .                           |            *
        |                           .                           |          DRMBSE
        |                           .                           |
        |                           .                           |            |
        |                           .                           |            |
        |                           .                           |            |
        |                           .                           |            |
        |                           .                           |            |
        |                           .                           |            |
        |-------------------------------------------------------|            |
        \                                                       \  \         |
        \                                                       \Cylinder n  |
        |                                                       |  /         |
        +-------------------------------------------------------+           \ /



        Note:  The bit map for each cylinder starts on a word boundary
        and contains as many full words as are needed for all of its
        pages.
                                                     Page 47


                           DRMCNT

Drum Count Table.  This table, indexed by cylinder,  records
the  free  page  count for the drum (logical swapping area).
The total free page count for all the cylinders is  kept  in
the storage word, DRMFRE.

Defined in:  STG

Referenced by:  SWPALC


                                   Format


          +-------------------------------------------------------+ / \
    DRMCNT|           Drum Free Page Count - Cylinder 0           |  |
          |-------------------------------------------------------|  |
          |                           .                           |  |
          |                           .                           |  |
          |                           .                           |
          |                           .                           |DRMMXB 
          |                           .                           |
          |                           .                           |  |
          \                           .                           \  |
          |-------------------------------------------------------|  |
          |           Drum Free Page Count - Cylinder n           |  |
          +-------------------------------------------------------+ \ /
                                                     Page 48


                           DSKSIZ

Disk Size Pointer Table.  This table  contains  pointers  to
the  disk  size  data  tables.  DSKSIZ is parallel to DSKUTP
which contains codes for the  known  disk  types.   When  an
entry  is  added  to  DSKUPT,  a corresponding entry must be
added to DSKSIZ to point to the correct size data  for  that
type of disk.

Defined in:  PHYSIO

Referenced by:  DSKALC



                                Format


        +-------------------------------------------------------+
DSKSIZ: |             Pointer to RP04 Table (DSKSZ0)            |
        |-------------------------------------------------------|
        |             Pointer to RP05 Table (DSKSZ0)            |
        |-------------------------------------------------------|
        |             Pointer to RP06 Table (DSKSZ1)            |
        |-------------------------------------------------------|
        |                    Future Development                 |
        |-------------------------------------------------------|
        |                    Future Development                 |
        |-------------------------------------------------------|
        |             Pointer to RM03 Table (DSKSZ3)            |
        +-------------------------------------------------------+
                                                     Page 49


                          DSKSZ`n

Disk Size Table (for type n).  The resident  table  contains
size data (for disks) based on type.

        n = 0   for RP04 and RP05
        n = 1   for RP06
        n = 3   for RM03

Defined in:  STG

Referenced by:  DSKALC, PHYSIO

                               Format

DSKSZ`n: +-------------------------------------------------+
/SEGPAG=0|                Sectors per Page                 |
         |-------------------------------------------------|
 SECCYL=1|              Sectors per Cylinder               |    
         |-------------------------------------------------|
 PAGCYL=2|               Pages per Cylinder                |    
         |-------------------------------------------------|
 CYLUNT=3|               Cylinders per Unit                |
         |-------------------------------------------------|
 SECUNT=4|                Sectors per Unit                 |
         |-------------------------------------------------|
 BTWCYL=5|   No. of Bit Words in Bit Table per Cylinder    |
         |-------------------------------------------------|
 MINFPG=6|  Minimum Free Pages for Free Choice Allocation  |
         |-------------------------------------------------|
 MAXFPU=7|    Pages per Unit for DSKASN turning point      |
         |-------------------------------------------------|
LPPCYL=10|            Lost Sectors per Surface             |
         |-------------------------------------------------|
SECSRF=11|               Sectors per Surface               |
         |-------------------------------------------------|
USSECU=12|       Microseconds per LATOPT sector unit       |
         +-------------------------------------------------+
                                                     Page 50


                           DSKUTP

Disk Unit Type.  This table contains the unit types used  by
the file system.                        

Defined in:  PHYSIO

Referenced by:  DSKALC, MSTR, PHYP4


                                Format


        +-------------------------------------------------------+ / \
DSKUTP: |           RP04 Disk Unit Code (.UTRP4 = 1)            |  |
        |-------------------------------------------------------|  |
        |           RP05 Disk Unit Code (.UTRP5 = 5)            |  |
        |-------------------------------------------------------|  |
        |           RP06 Disk Unit Code (.UTRP6 = 6)            |
        |-------------------------------------------------------| NDSKUT
        |                  Future Development                   |
        |-------------------------------------------------------|  |
        |                  Future Development                   |  |
        |-------------------------------------------------------|  |
        |           RM03 Disk Unit Code (.UTRM3 = 11)           |  |
        +-------------------------------------------------------+ \ /
                                                     Page 51


                            DST

Drum Status Table.  This table is indexed as a  function  of
the  drum  (swapping  space)  address.   The  routine  GDSTX
converts a drum address into a DST index.  The DST holds the
address  of  the  next lower level of storage (usually disk)
for the page stored at that address on the drum.

BWRBIT (bit 11) indicates if the page has been changed since
being read from the lower level storage.  The page will only
be copied back on to the lower level storage  if  BWRBIT  is
set (i.e., page modified) when the page is no longer in use.
A slot no longer in use contains a -1.

Defined in:  STG, PROLOG

Referenced by:  PAGEM

Index:  Drum page number

                                Format

                         11   14                              35
        +-------------------------------------------------------+  / \
DST:    |                ||  |         Storage Address          |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NDST
        |                           .                           | 
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /
                                                     Page 52


                      DTE-STORAGE-AREA

DTE Storage Area.  This storage area  contains  storage  for
each  DTE.   It  contains  the  Communication  Area for each
processor  in  COMBAS,  the  linked  output  packet   queues
(pointed  to  by  DTEQS),  the  DTE input buffers, and local
storage (i.e., ACs, PC, & PDL) for the DTE Protocol Handler,
DTESRV.

A packet in the COMQ area  must  be  reformatted  to  RSX20F
protocol  and  stored  in  PKTADR before being sent over the
DTE.  The before and  after  packet  formats  are  described
below.

Two single packets, SNGPK1 and SNGPK2 (already formatted  as
direct  packets  to  RSX20F  protocol  -  See below) are set
aside for the DTSNGL routine.  This routine  is  responsible
for  activating lines and sending single characters over the
DTE if the output buffer has only one character.

Normally output buffer  characters  are  sent  via  indirect
packets over the DTE, where the indirect packet (after being
reformatted and stored in PKTADR) is sent first followed  by
the line's output buffer characters.

Defined in:  STG

Referenced by:  DTESRV, SPRSRV, MEXEC, SCHED


        +-------------------------------------------------------+
UPFLAG: |          Word to Generate Continued Message           |
        |-------------------------------------------------------|
LOAD11: |              Says if -11 Needs to Reload              |
        |-------------------------------------------------------|
LODFRK: |        Handle of Monitor Fork Doing -11 Reboot        |
        |-------------------------------------------------------|
DTEDTE: |                 The Interrupting DTE                  |
        |-------------------------------------------------------|
CTYUNT: |              FE Physical Unit for TS TTY              |
        |-------------------------------------------------------| / \
DTEQS:  |             Drive Queue Header for DTE 1              |  |
        |          (Ptr. to 1st Queued Packet in COMQ)          |  
        \                           .                           \ DTEN
        |                           .                           |  
        |             Driver Queue Header for DTE n             |  |
        |-------------------------------------------------------| \ /
COMQ:   |                                                       |*/ \
        |                                                       |  |
        \                Area for Queue Packets                 \  |
        \                 (=Packet Size * ^D20)                 \ 
        \                                                       \ QPKT1
        |                                                       |  
        |                                                       |  |
        |                                                       |  |
                                                     Page 53


        |-------------------------------------------------------| \ /
COMH:   |   Queue Header (Points to 1st Free Packet in COMQ)    |
        |-------------------------------------------------------| / \
DTESTS: |                   DTE 1 Status Word                   |* |
        |                           .                           |
        \                           .                           \ DTEN
        |                   DTE n Status Word                   |  |
        |-------------------------------------------------------| \ /
DTEST1: |              DTE 1 Secondary Status Word              |*/ \
        |                           .                           |  |
        \                           .                           \ DTEN
        |              DTE n Secondary Status Word              |  |
        |-------------------------------------------------------| \ /
DTBFWD: |                Hdr. Word for DTE 1 Buf                | 
        |   (Ptr. to 2nd Input Buf,, Ptr. to 1st Input Buf)     |
        \                           .                           \
        |                           .                           |
        |             Header Word for DTE n Buffer              |
        |-------------------------------------------------------|
DTETRA: |             Interrupt Return PC for DTE 1             |
        |                           .                           |
        |-------------------------------------------------------|
        |                           .                           |
        |             Interrupt Return PC for DTE 2             |
        |-------------------------------------------------------| / \
DTESKP: |                                                       |  |
        |                                                       | 
        \                    Local PDL Stack                    \ DTESZ
        |                                                       |
        |                                                       |  |
        |-------------------------------------------------------| \ /
DTEACB: |                                                       | / \
        \                   Block to Save ACs                   \  |
        |                                                       | 16
        |-------------------------------------------------------| \ /
DTEIND: |        Storage for Indirect Function for DTE 1        |*/ \
        |                           .                           |  |
        \                           .                           \ DTEN
        |        Storage for Indirect Function for DTE n        |  |
        |-------------------------------------------------------| \ /
PKTADR: |               Storage for Queue Packets               | / \
        |        (One 3-Word Packet/RSX20F Protocol DTE)        |  |
        \                                                       \ PKTSZ1
        |                                                       |  |
        |-------------------------------------------------------| \ /
COMBUF: | Processor #  |    Index into COMBAS to get to this    | / \--  --
        |            4 |         Processor's Comm Area          |  |  |   |
        |-------------------------------------------------------|  |  |   |
        |            3 |                  ''                    |DTEN+1   |
        |-------------------------------------------------------|  |      |
        |            2 |                  ''                    |  |Header|
        |-------------------------------------------------------|  |Area  |
        |            1 |                  ''                    |  |  |   |
        |-------------------------------------------------------|  |  |   |
        |            0 |                  ''                    |  |  |   |
                                                     Page 54


        |-------------------------------------------------------| \ / --  |
COMBAS: |                   KL10 "Owned" Area                   |--       |
        |-------------------------------------------------------| |       |
        |                    "To" DTE1 Area                     | |       |
        |-------------------------------------------------------| |       |
        |                    "To" DTE2 Area                     |  Master |
        |-------------------------------------------------------| Process |
        |                           .                           |   Comm  |
        |                           .                           |   Area  |
        |                           .                           | |       |
        |-------------------------------------------------------| Communi-|
        |                    "To" DTEn Area                     | |cation |
        |-------------------------------------------------------|--Region |
        |                                                       |--       |
        |                   DTE1 "Owned" Area                   |  DTE1   |
        |                                                       |  Comm   |
        |-------------------------------------------------------|  Area   |
        |                    "To" KL10 Area                     | |       |
        |-------------------------------------------------------| |       |
        |                           .                           | |       |
        |                           .                           | |       |
        |                           .                           | |       |
        |-------------------------------------------------------|--       |
        |                                                       |--       |
        |                   DTEn "Owned" Area                   | |  DTEn |
        |                                                       |    Comm |
        |-------------------------------------------------------| |  Area |
        |                    "To" KL10 Area                     |--      --
        |-------------------------------------------------------| / \
TAD11:  \                 Time Packet from -11                  \  3
        |-------------------------------------------------------| \ /
        \                                                       \ / \
TO11TM: \                  Time Packet to -11                   \  3
        |-------------------------------------------------------| \ /
        \                                                       \ / \
KLIDTA: \                    KLINIK Data Base                   \ KLISIZ
        |-------------------------------------------------------| \ /
SNGPK1: |              Single-Packet-1 Header Word              |
        |-------------------------------------------------------| / \
        \                Packet Data (5 Words)                  \  5
        |                                                       | \ /
        |-------------------------------------------------------|
SNGPK2: |              Single-Packet-2 Header Word              |
        |-------------------------------------------------------| / \
        \                Packet Data (5 Words)                  \  5
        |                                                       |  |
        +-------------------------------------------------------+ \ /
                                                     Page 55


  DTESTS
    0  1  2  3  4  5  6          17 18            29 30          35
   +---------------------------------------------------------------+
   |  |  |  |  |  |  |    DTEB1    |     DTEBC      |     DTEST    |
   +---------------------------------------------------------------+


        Bits         Pointer              Content 

         0           DTERL           If set, DTE exists
         1           DTEBF           Says which buffer is in use
                                      for RSX20 protocol
         2           DTBLK           For MCB, to -10 is blocked
                                      on free space
         3           DTRLD           If set, -11 is being reloaded
         4           DTKAC           If set, -11 is ill
         5           DTSTI           Status packet is split
        6-17         DTEB1           Byte count of list transfer
       18-29         DTEBC           Byte count remaining for
                                      subsequent transfer
       30-35         DTEST           DTE status
                                        DTET10=1 
                                           KL10 is receiving last
                                            fragment of message
                                        DTE11=2 
                                           -11 is receiving bytes
                                        DTE11I=4 
                                           -11 is receiving an 
                                            indirect queue entry
                                        DTE1F=10 
                                           KL10 is receiving 1st 
                                            fragment of a message
                                                     Page 56


        DTEST1 Is parallel to DTESTS  and  contains  current
        operation       data  and  special  request bits for
        "To" -11 conditions.


               0                15 16               31  32  33  34  35
              +-------------------------------------------------------+
              |DT1FC              |DT1DV              |   |   |       |
              +----------------------------------------------------------+
        
                Bits         Pointer         Contents
        
                0-15         DT1FC        Current function code
               16-31         DT1DV        Current device code
                32           DT1TM        -11 wants time of day
                33           DT1ID        Waiting for indirect
                                           setup
        
        
        DTEIND (Storage for indirect packets)


               0          7 8         15   16    17                    35
              +----------------------------------------------------------+
              |INUNT       |INCNT       |       |                        |
              +----------------------------------------------------------+
        
                Bits        Pointer         Contents
        
                0-7         INUNT           Unit
                8-15        INCNT           Count
                16          INVLD           If set, says unit
                                             field is invalid
                                                     Page 57


      COMQ Area for queue packets where a packet (5 words in
      length) has the form:

             0                          17 18                           35
            +-------------------------------------------------------------+
          0 |QINT                         |QLINK                          |
            |   Int Loc for this Function |   Link to Next Packet         |
            |-----------------------------|-------------------------------|
          1 |QFNC                         |QDEV                           |
      QNSPH |   Function Word for this    |   DTE Dev. Code for this      |
            |    Request                  |    Request                    |
            |-----------------------------|-------------------------------|
          2 |QLIN                         |QMODE    |19 QCNT            35|
            |   Device Unit #             |indirect |  Byte Count or Byte |
            |                             |Data Must|   or 0              |
            |                             |be Byte  |                     |
            |                             |Mode     |                     |
            |-------------------------------------------------------------|
          3 |QPNTR                                                        |
            |   Byte Pointer for Indirect Operation or Local 8-bit Datum  |
            |    if QCNT = 0                                              |
            |-------------------------------------------------------------|
          4 |QCOD                                                         |
            |   Unique Code Returned to Interrupt Routine, TTYINT         |
            +-------------------------------------------------------------+
      
            COMQ area is currently assembled for room of ^D20 packets.
      
      
      PKTADR
      
         Storage for currently activated DTE packet for each DTE (Packet
         taken from the linked list of packets on the queue in COMQ and
         place here).
                                                     Page 58


                The packet has the following form:
      
          0                    15 16             31  32    35
         +---------------------------------------------------+
       0 |HDCNT                  |HDFNC             |        |
         |     Count             |    Function      |        |
         |---------------------------------------------------|
       1 |HDDEV                  |HDSPR             |        |
         |     Device Code       |    Spare         |        |
         |---------------------------------------------------|
         |0         7|8        15|                           |
       2 |HDLIN      |HDDAT      |                           |
         |   Line #  |    Datum* |                           |
         |-----------------------|                           |
         |0         or         15|                           |
         |HDDT1                  |                           |
         |    Dataum for Single  |                           |
         |     Datum Packet      |                           |
         +---------------------------------------------------+
      
         * Datum could be a character (direct packet case) or
           Max # of characters to be sent (indirect packet case)
                                                     Page 59


                   0              15 16               31  32   35
        SNGPK1/2  +----------------------------------------------+
                  |  Flags           |Link to Next Packet|       |
                  |----------------------------------------------|
                  |Packet Byte Count |     Function      |       |
                  |----------------------------------------------|
                  |     Device       |       Spare       |       |
                  |----------------------------------------------|
                  | Line #  | Datum  | Line #  | Datum   |       |
                  |----------------------------------------------|
                  | Line #  | Datum  | Line #  | Datum   |       |
                  |----------------------------------------------|
                  | Line #  | Datum  | Line #  | Datum   |       |
                  +----------------------------------------------+
        
        
                      0 1 2               16               31
                     +---------------------------------------------+
        Header Word  | | | |             |Link to Next Packet|     |
                     +---------------------------------------------+
        
        
                     Symbol           Bits             Contents
        
                     SNGONQ            0             On the DTE packet
                                                      queue pointed to by
                                                      DTEQS
                     SNGAVL            1             Packet has space
                                                      available
                     SNGACT            2             Packet active (i.e.
                                                      DTE processing it)
                                     16-31           Link to next packet
                                                     Page 60


        COMBAS
          "Owned" Area Block Format
        
                      0   1 2 3 4 5 6  11 12  16 17  19 20          35
                   +--------------------------------------------------+
                 0 |CMTEN|CMVER|   |CPVER| CMNPR| CMSIZ|  CMNAM       |*
                   |     |     |   |     |      |      |Processor Name|
                   |--------------------------------------------------|
                 1 |CMLNK                                             |
                   |            Pointer to Next Processor             |
                   |--------------------------------------------------|
                   |                                                  |
                   \                                                  \
                   |                                                  |
                   |--------------------------------------------------|
         KPALIV=5  |CMKAC                                             |
                   |           Processor Keep Alive Count             |
                   |--------------------------------------------------|
         CMPCW=6   |                    PC Word                       |
                   |--------------------------------------------------|
         CMPIWD=7  |                 CONI PI, Word                    |
                   |--------------------------------------------------|
         CMPGWD=10 |                CONI PAG, Word                    |
                   |--------------------------------------------------|
         CMPDWD=11 |                DATAI PAG, Word                   |
                   |--------------------------------------------------|
         CMAPRW=12 |                CONI APR, Word                    |
                   |--------------------------------------------------|
         CMDAPR=13 |                DATAI APR, Word                   |
                   |--------------------------------------------------|
                14 |                                                  |
                   \                                                  \
                   |                                                  |
                17 +--------------------------------------------------+
                                                     Page 61


        Word 0   0 1 2 3 4 5 6    11 12   16 17  19 20     
                +--------------------------------------------------+
                | |     |   | CPVER | CMNPR |      |CMNAM          |
                | |     |   |       |       |      | Processor Name|
                +--------------------------------------------------+

                Bits       Pointer          Contents

                 0         CMTEN        Set if area belongs to KL10
                1-3        CMVER        Communication area version
                                         number
                6-11       CPVER        Protocol version number
               12-16       CMNPR        Number of processors
                                         represented in this
                                         area (including owner)
               17-19       CMSIZ        Size of area in 8-word
                                         blocks
               20-35       CMNAM        Processor name 
                                         (= serial number)
                                                     Page 62


        "To" Area Block Format
        
              0   1     2   3       11 16 17 19 20                         35
           +-----------------------------------------------------------------+
         0 |CMPRO|CMDTE|CMDTN|     |CMVRR|CMSIZ|CMPNM                        |*
           |     |     |     |     |     |     | "To" Processor No.          |
           |-----------------------------------------------------------------|
         1 |CMPPT                                                            |
           |  Pointer to "To" Processor's Owned Communication Area           |
           |-----------------------------------------------------------------|
         2 |  0  |  1  |  2  |  3  |4 12| 13 |14 16| 17  | 18| 19|20 27|28 35|*
           |CMPWF|CML11|CMINI|CMTST|    |CMQP|     |CMFND|   |   |CMOIC|CM1IC|
           |-----------------------------------------------------------------|
         3 |0     3|4                            19|20                     35|
           |CMTMD  |CMPCT                          |CMQCT                    |
           |Mode of| Piecemeal Ctr. (Bits 0-19 Used|  Count of Words in      |
           | Xfer  |  by Prot. Ver. VNMCB Only)    |   Current Queue         |
           |-----------------------------------------------------------------|
         4 |CMRLF                                                            |
           |              Reload Parameter for "To" Processor                |
           |-----------------------------------------------------------------|
         5 |CMKAK                                                            |
           |  Owning Processor's Copy of "To" Processor's Keep Alive Count   |
           +-----------------------------------------------------------------+
        
        
                   0 1 2 3          11  16 17  19 20                35
                  +-----------------------------------------------------+
           Word 0 | | |   |        |CMVRR |CMSIZ |CMPNM                 |
                  | | |   |        |      |      | "To" Processor Number|
                  +-----------------------------------------------------+
        
                          Bits        Pointer      Contents
        
                           0          CMPRO      If set, it implies connected
                                                  to a KL10
                           1          CMDTE      If set, there is a DTE
                                                  connecting this processor
                                                  and owning processor
                          2-3         CMDTN      If CMDTE is set, this is
                                                  the number of that
                                                  connecting DTE
                         11-16        CMVRR      Protocol in use by the two
                                                  processors
                         17-19        CMSIZ      Size of "to" area in
                                                  8-word blocks
                         20-35        CMPNM       "To" processor number
                                                     Page 63


                   0 1 2 3 4    12 13 14  16 17 18 19 20     27 28     35
                  +------------------------------------------------------+
           Word 2 | | | | |       |  |      |  |  |  |CMOIC    |CM1IC    |
                  | | | | |       |  |      |  |  |  |To 10IC  |To 11IC  |
                  | | | | |       |  |      |  |  |  |for Queue|for Queue|
                  | | | | |       |  |      |  |  |  |Xfer     |Xfer     |
                  +------------------------------------------------------+

        Symbol       Bits         Pointer          Contents

                      0           CMPWF        Power fail indicator -11
                      1           CML11        Wants reload (set by -11)
                      2           CMINI        Initialization bit for 
                                                MCB protocol only
                      3           CMTST        Valid examine if set
                                                (should always be set)
                     13           CMQP         Set if using queued
                                                protocol
                     17           CMFND        -11 doing full word
                                                transfer (set by -11)
        CMIP         18                        -11 doing indirect
                                                transfer
        CMTOT        19                        "Toit" bit. Set to 1 by
                                                KL10 in -11's section
                                                of -10's Comm area
                                                after -11 sets QMode bit
                                                 or increments Q-count,
                                                 and after -10 processes
                                                 the doorbell.  

                                                Cleared by KL10 after 
                                                 receiving T010DN.
                                                 Assures -11 that the
                                                 KL10 has not
                                                 lost a T010DN interrupt

                   20-27          CMOIC        -11s wrap around count
                                                 of direct Q transfer
                   28-35          CM1IC         KL10's wrap around count
                                                 of direct Q transfers.
                                                     Page 64


                           DTEDTV

DTE Protocol Device Dispatch Table.  The  entries  with  the
dispatch address, TTYDTV are for the CTY, DL11, DH11 and DLS
devices.

Defined in:  STG

Referenced by:  DTESRV

                                Format

        +-------------------------------------------------------+
DTEDTV: |              Reserved for Unknown Device              |
        |-------------------------------------------------------|
        |                        TTYDTV                         |
        |-------------------------------------------------------|
        |                        TTYDTV                         |
        |-------------------------------------------------------|
        |                        TTYDTV                         |
        |-------------------------------------------------------|
        |                        TTYDTV                         |
        |-------------------------------------------------------|
        |                        LPTDTV                         |
        |-------------------------------------------------------|
        |                        CDRDTV                         |
        |-------------------------------------------------------|
        |                  0 (Unknown Device)                   |
        |-------------------------------------------------------|
        |                        FEDTV                          |
        +-------------------------------------------------------+
                                                     Page 65


                   ENQ/DEQ - STORAGE AREA

Enqueue/Dequeue Storage Area.  The non-resident  local  area
for the ENQ/DEQ Facilty is illustrated first followed by the
resident bit tables, ENFKTB and LCKDBT.  A bit is set in the
ENFKTB  bit  table  if  the  fork  should  be  woken  up  or
interrupted  because  it  owns  a  lock.   (The  Scheduler's
wake-up test routine address is ENQTST.)

Defined in:  STG

Referenced by:  ENQ, IPCF, DIRECT


                       Format

        +--------------------------------------------------+ / \
HSHTBL:*|                                                  |  |
        \                  Hash Table for                  \
        \                     ENQ Locks                    \ HSHLEN
        \           (Name/Number of Lock hashed)           \
        |                                                  |  |
        |--------------------------------------------------| \ /
ENQLOK: |          Data Base Lock For ENQ and DEQ          |
        |                   (-1 if Free)                   |
        |--------------------------------------------------|
ENQSPC: |                Count of Free Space               |
        |                Available for ENQ's               |
        |--------------------------------------------------|
ENQLTL: |              List of Long Term Locks             |
        |--------------------------------------------------|
ENQLTS: |           Time of next Garbage Collect           |
        +--------------------------------------------------+
                                                     Page 66


Resident Storage:

        +--------------------------------------------------+ / \
ENFKTB: | | | | | . .                                      |  |
        |--------------------------------------------------| ENFKTL
        |            Wake-up Table (1 bit/Fork)            |  |
        |                                                  |  |
        |--------------------------------------------------| \ /
LCKDBT: | | | | | . .                                      | / \
        |--------------------------------------------------|  |
        |           Bit Tbl for DIR Lock ENQ/DEQ           | LCKDBN
        |                   (1 bit/fork)                   |  |
        +--------------------------------------------------+ \ /


       *The name (or identifying number) of a lock block
        is hashed to provide a number; This number, modulo
        the size of the hash table is used as an index
        into HSHTBL.  If the hashing algorithm yields the
        same index for more than one lock block name, the
        lock blocks will be linked together; the HSHTBL
        entry will be the linked list header.
                                                     Page 67


                       ENQ-LOCK-BLOCK

Enqueue Lock Block.  Each resource is described  in  a  lock
block.   The  lock block is created at the time of the first
request.

Defined in:  ENQ

Referenced by:  ENQ

                                  Format

         +-------------------------------------------------------+
         |  ENQLHC                   |  ENQNHC                   |
      0  |   Back Pointer to Last    |      Pointer to Next      |
         | Lock-Block on Hash Chain  | Lock-Block on Hash Chain  |
         |-------------------------------------------------------|
         |  ENQLLQ                   |  ENQNLQ                   |
      1  |      Back Pointer to      |    Forward Pointer to     |
         |   Last Q-Block on Queue   |  First Q-Block on Queue   |
         |-------------------------------------------------------|
         |  ENQFLG         |         |  ENQLVL                   |
      2  |      Flags      |         |       Level Number        |
         |                 |         |       of this Lock        |
         |-------------------------------------------------------|
         |  ENQTR                    |  ENQRR                    |
      3  |   Total # of Resources    |    Remaining Number of    |
         |       in this Pool        |  Resources in this Pool   |
         |-------------------------------------------------------|
         |  ENQTS                                                |
      4  |                      Time Stamp                       |
         |              Time of Last Request Locked              |
         |-------------------------------------------------------|
         |  ENQFBP                   |  ENQLT                    |
.ENQLT=5 |    Free Block Pointer     |    Long Term Lock List    |
         |      to Free Q-Block      |       for this Job        |
         |-------------------------------------------------------|
         |  ENQOFN                   |  ENQLEN                   |
      6  |    OFN, or -2, or -3,     |      Length of this       |
         |  or 400000 + Job Number   |        Lock-Block         |
         |-------------------------------------------------------|
         |  ENQNMS                   |                           |
      7  |    Number of Words in     |                           |
         |      the Mask Block       |                           |
         |-------------------------------------------------------|
         |  ENQTXT             ASCIZ String                      |
.ENTXT=10|                          or                           |
         |                  500000 + User Code                   |
         +-------------------------------------------------------+
                                                     Page 68





          0           11 12        17 18                       35
         +-------------------------------------------------------+
 Word 0  | ENQFLG       |            | ENQLVL                    |
         |   Flags      |            |   Level # of this Lock    |
         +-------------------------------------------------------+

          Symbol     Bits    Pointer       Meaning

        EN.LTL=40      6                   Long Term Block
        EN.INV=20      7                   This Q-Block is invisible
        EN.LOK=10      8                   The Q-Block has the Lock
                                            Locked.
        EN.TXT=4       9                   This Block has a Text
                                            String Identity.
        EN.EXC=2      10                   Request is Exclusive
        EN.LB=1       11                   This is the Lock-Block
                     13-17   ENQCHN        PSI Channel (-1 means job
                                            Blocked)
                     18-35   ENQLVL        Level # of this lock.
                                                     Page 69


                            EPT

Executive Process Table.  This memory resident table pointed
to  by  the  Executive  Base  Register  (EBR),  contains the
vectored dispatch addresses for system events.   All  device
interrupts  pass  control  to  a specific offset position in
this table.

This table also includes the executive  section  map  table,
the time of day clock and arithmetic trap instructions which
are executed when arithmetic conditions occur  in  executive
mode.

Locations 444 to 457 are reserved for software and  used  by
DTESRV.

Defined In:  STG

Referenced by:  APRSRV, DTESRV, MEXEC, PHYH11, PHYH2

                              Format

                +-------------------------------------+
         KIEPT: |     Eight Channel Logout Areas      |
                |                                     |
                |Each: 0 Initial Channel Command      |
                \      1 Gets Channel Status Word     \
                |      2 Gets Last Updated Command    |
                |      3 Reserved for Channel's       |
                \        Vectored Interrupt Location  \
                |                                     |
                |                                     |
                |                                     |
        KIEPT+37|                                     |
                |-------------------------------------|
              40|                                     |
              41|              Reserved               |
                |-------------------------------------|
              42|                                     |
                \Standard Priority Interrupt Instruc. \
              57|                                     |
                |-------------------------------------|
              60|                                     |
                |  Four Channel Block Fill Words      |
              63|                                     |
                |-------------------------------------|
              64|                                     |
                \              Reserved               \
               .|                                     |
              77|                                     |
                |-------------------------------------|
SMTEPT=KIEPT+100|    Pointer to SM10 Vector Table     |
                |          (if 2020 System)           |
                |-------------------------------------|
             101|                                     |
                                                     Page 70


                |                                     |
                \              Reserved               \
             137|                                     |
                |-------------------------------------|
                |  Four 8-word DTE20 Control Blocks   |
DTEEBP=KIEPT+140|  Each: 0 To -11 Byte Pointer        |
DTETBP=KIEPT+141|        1 To -10 Byte Pointer        |
DTEINT=KIEPT+142|        2 Interrupt Location         |
             143|        3 Reserved                   |
DTEEPW=KIEPT+144|        4 Examine Protection Word    |
DTEERW=KIEPT+145|        5 Examine Relocation Word    |
DTEDPW=KIEPT+146|        6 Deposit Protection Word    |
DTEDRW=KIEPT+147|        7 Deposit Relocation Word    |
                |-------------------------------------|
                |                                     |
                \         DTE1 Control Block          \
                |                                     |
                |-------------------------------------|
                |                                     |
                \         DTE2 Control Block          \
                |                                     |
                |-------------------------------------|
                |                                     |
                \         DTE3 Control Block          \
             177|                                     |
                |-------------------------------------|
EPTMHI=KIEPT+200|                                     |
                |                                     |
                |                                     |
                |                                     |
                |        Available to Software        |
                |                                     |
                |                                     |
                |                                     |
             417|                                     |
                |-------------------------------------|
EPTPTI=KIEPT+420|      LUUO from Executive Mode       |
                |              (.LUTRP)*              |
                |-------------------------------------|
             421| Executive Arithmetic Overflow Trap  |
                |         Instruction (JFCL)*         |
                |-------------------------------------|
             422|    Executive Stack Overflow trap    |
                |        Instruction (.PDOVT)*        |
                |-------------------------------------|
             423|  Executive Trap 3 Trap Instruction  |
                |               (JFCL)*               |
                |-------------------------------------|
             424|                                     |
                \              Reserved               \
             437|                                     |
                |-------------------------------------|
             440|                                     |
                \        Reserved for Software        \
             443|                                     |
                                                     Page 71


                |-------------------------------------|
DTEFLG=KIEPT+444|       Operation Complete Flag       |
                |-------------------------------------|
DTECFK=KIEPT+445|        Clock Interrupt Flag         |
                |-------------------------------------|
DTECKI=KIEPT+446|     Clock Interrupt Instruction     |
                |-------------------------------------|
DTET11=KIEPT+447|          "To" 11 Argument           |
                |-------------------------------------|
DTEF11=KIEPT+450|         "From" 11 Argument          |
                |-------------------------------------|
DTECMD=KIEPT+451|            Command Word             |
                |-------------------------------------|
DTESEQ=KIEPT+452|   DTE20 Operation Sequence Number   |
                |-------------------------------------|
DTEOPR=KIEPT+453|     Operation in Progress Flag      |
                |-------------------------------------|
DTECHR=KIEPT+454|        Last Typed Character         |
                |-------------------------------------|
DTETMD=KIEPT+455|  Monitor TTY Output Complete Flag   |
                |-------------------------------------|
DTEMTI=KIEPT+456|       Monitor TTY Input Flag        |
                |-------------------------------------|
DTESWR=KIEPT+457|       Console Switch Register       |
                |-------------------------------------|
             460|                                     |
                \        Reserved for Software        \
             477|                                     |
                |-------------------------------------|
             500|                                     |
                \              Reserved               \
             507|                                     |
                |-------------------------------------|
TIMBAS=KIEPT+510|                                     |
                |              Time Base              |
             511|                                     |
                |-------------------------------------|
             512|                                     |
                |     Performance Analysis Count      |
             513|                                     |
                |-------------------------------------|
TIMVIL=KIEPT+514| Internal Counter Interrupt Instruc. |
                |-------------------------------------|
MSECTB=KIEPT+540|           EXEC SECTION 0            |
                |                                     |
                \                                     \
                |                                     |
             577|           EXEC SECTION 37           |
                |-------------------------------------|
EPTMLO=KIEPT+600|                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                \        Available to Software        \
                                                     Page 72


                \                                     \
                |                                     |
                |                                     |
                |                                     |
             777|                                     |
                +-------------------------------------+


    *  These values are placed into the table when the EPT is
       initialized at system startup.
                                                     Page 73


                      EXEC-PG-MAP-TBL

Executive Page Map Table.   This  512-word  memory  resident
table  holds  or points to other tables that hold all of the
mapping information needed  by  the  firmware  to  translate
executive  (monitor)  virtual  addresses  in a given section
into physical memory addresses.  It  is  pointed  to  by  an
entry  in  the  monitor's  section  table  in  the Executive
Process Table (EPT).

The four possible formats for an entry in this table  (i.e.,
Immediate,   shared,   indirect   or   null   pointers)  are
illustrated below.   The  details  of  these  four  possible
pointer  words  as  well  as the mechanics of the virtual to
physical translation process for a monitor page is identical
to   that   described  for  the  User-Page  Map  Table  (See
User-Pg-Map-Tbl)

Defined in:  STG

Referenced by:  All Monitor Modules

                              Format

MMAP*:  +-------------------------------------------------------+
       0|                                                       |  / \
        |                   Immediate Pointer                   |   |
        |-------------------------------------------------------|   |
        |0    2| 3         8|       | 12                      35|   |
        | Op   |Access Bits |       |    STGADR                 |   |   
        | Code |            |       |  Storage Address          |   |
        |  1   |            |       |                           |   |
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |                                                       |   |
        |                    Shared Pointer                     |   |
        |-------------------------------------------------------|   |
        |0  2 |3        8|          |18                       35|   |
        | Op  | Access   |          | SPTX                      |   |
        | Code|   Bits   |          |  SPT. index               |   |
        |  2  |          |          |  (Holds Pg's Stor Adr.)   |
        |-------------------------------------------------------| Virtual
        |                          or                           |  Pg #
        |                                                       |0-777octal
        |                   Indirect Pointer                    |
        |-------------------------------------------------------|   |
        |0  2 |3      8 |9       17 |18                      35 |   |
        | Op  | Access  | IPPGN     | SPTX                      |   |
        | Code|  Bits   |     PN    | SPT index                 |   |
        |  3  |         |           | (Holds Pg Tb's Stor. Adr) |   |
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |                                                       |   |
        |                     Null Pointer                      |   |
        |-------------------------------------------------------|   |
                                                     Page 74


        |0  2 |3         8|                                     |   |
        |Op   |Access Bits|         0 (Nonexistent Pg)          |   |
        |Code |           |                                     |   |
        |  0  |      0    |                                     |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+

    * Currently MMAP is the monitor's page map table for section 0 
      and section 1.  The layout of the monitor's virtual address
      space for section 0 is described in Appendix B of the Monitor
      Structures Book.
                                                     Page 75


                            FDB

File Description Block.  All attributes of a file are stored
in  its  description  block  (FDB)  maintained in the file's
directory.  An FDB is built in the  directory's  free  space
area  when  a  file is created.  This table is referenced by
the DIR table.

Defined in:  PROLOG, MONSYM

Referenced by:  DISC, DIRECT, DSKALC, GTJEN, JSYSA, JSYSF,
                FILINI, LINEPR, IO, SYSERR, DTESRV




        +-------------------------------------------------------+
        |0                        17|18    23|24              35|
        |  FBTYP                    |  FBVER |  FBLEN           |
.FBHDR  |          400100           | Ver. # |      Length      |
        |-------------------------------------------------------|
        |  FBFLG                    |                           |
.FBCTL  |          Flags            |                           |
        |-------------------------------------------------------|
        |  FBEXL                                                |
.FBEXL  |                 Link to FDB of Next Extension         \
        |-------------------------------------------------------|
        |  FBADR                                                |
.FBADR  |          Disk Address of File's Index Block           |
        |-------------------------------------------------------|
        |  FBPRT                    |                           |
.FBPRT  |          500000           |     File Access Bits      |
        |-------------------------------------------------------|
        |  FBCRE                                                |
.FBCRE  |          Date and Time of Last Write to File          |
        |-------------------------------------------------------|
        |  FBLW0                    |  FBAT0                    |
.FBUSE  |   DIR # of Last Writer    |      DIR # of Author      |
        |-------------------------------------------------------|
        |  FBAUT                                                |
.FBAUT  |               Pointer to Author String                |
        |-------------------------------------------------------|
        |  FBLWR                                                |
.FBLWR  |             Pointer to Last Writer String             |
        |-------------------------------------------------------|
        |  FBGEN                    |FBDRN                      |
.FBGEN  |     Generation Number     | Dir.# (if it's a Dir File)|
        |-------------------------------------------------------|
        |  FBACT                                                |
        |              500000,,0 + Account Number               |
        |                          or                           |
.FBACT  |               Pointer to Account String               |
        |-------------------------------------------------------|
        |0      5|6     11|  |14  17|18                       35|
        | FBGNR  | FBBSZ  |  |FBMOD |  FBNPG                    |
                                                     Page 76


.FBBYV  |# Gens. |Byte Sz |  | Mode |  # of Pages in File       |
        |-------------------------------------------------------|
        |  FBSIZ                                                |
.FBSIZ  |                  # of Bytes in File                   |
        |-------------------------------------------------------|
        |  FBCRV                                                |
.FBCRV  |               Date and Time of Creation               |
        |-------------------------------------------------------|
        |  FBWRT                                                |
.FBWRT  |           Date and Time of Last User Write            |
        |-------------------------------------------------------|
        |  FBREF                                                |
.FBREF  |         Date and Time of Last Nonwrite Access         |
        |-------------------------------------------------------|
        |  FBNWR                    |  FBNRF                    |
.FBCNT  |        # of Writes        |      # of References      |
        |-------------------------------------------------------|
        |  FBBK0                                                |
.FBBK0  |                    Backup Word #1                     |
        |-------------------------------------------------------|
        |  FBBK1                                                |
.FBBK1  |                    Backup Word #2                     |
        |-------------------------------------------------------|
        |  FBBK2                                                |
.FBBK2  |                    Backup Word #3                     |
        |-------------------------------------------------------|
        |  FBBK3                                                |
.FBBK3  |                    Backup Word #4                     |
        |-------------------------------------------------------|
        |  FBBK4                                                |
.FBBK4  |                    Backup Word #5                     |
        |-------------------------------------------------------|
        |  FBUSW                                                |
.FBUSW  |                  User Settable Word                   |
        |-------------------------------------------------------|
        |  FBGNL                                                |
.FBGNL  |            Link to FDB of Next Generation             |
        |-------------------------------------------------------|
        |  FBNAM                                                |
.FBNAM  |              Pointer to File Name Block               |
        |-------------------------------------------------------|
        |  FBEXT                                                |
.FBEXT  |              Pointer to Extension Block               |
        |-------------------------------------------------------|
        |                                                       |
.FBLWR  |             Pointer to Last Writer String             |
        |                                                       |
        +-------------------------------------------------------+
                                                     Page 77




            0 1 2 3 4 5 6 7 8 9 10   13 14    17 18         27 28      35
           +-------------------------------------------------------------+
    .FBCTL | | | | | | | | | | |       |       |              |          |
           +-------------------------------------------------------------+


                Symbol     Bits     Pointer     Content

                FB%%TMP       0                 File is temporary
                FB%%PRM       1                 File is permanent
                FB%%NEX       2                 No extension for this file 
                                                yes; file doesn't really
                                                exist.
                FB%%DEL       3                 File is deleted
                FB%%NXF       4                 File doesn't exist (first 
                                                write not complete)
                FB%%LNG       5                 Long file
                FB%%SHT       6
                FB%%DIR       7                 File is a directory
                FB%%NOD       8                 File is not saved by backup
                                                 system
                FB%%BAT       9                 File may have bad pages
                FB%%FCF     14%-17               File class field
                                                   0 = .FBNRM   Not an
                                                                 RMS file
                                                   1 = .FBRMS   RMS file

        Note:   See Monitor Call's Reference Manual (Chapter 2) for
                more information.
                                                     Page 78


                FILE DESCRIPTOR BLOCK (FDB)






     The following diagrams show the layout of the  FDB  for
files  created  by  Release  4.   New or changed entries are
marked with a bar at the left.


        +-------------------------------------------------+
        !0                     17!18   23!24            35!
        !  FBTYP                 ! FBVER !  FBLEN         !
 .FBHDR !          400100        ! Ver. #!      Length    !
        !-------------------------------------------------!
|       !  FBFLG                 !                        !
|.FBCTL !          Flags         !                        !
        !-------------------------------------------------!
        !  FBEXL                                          !
 .FBEXL !              Link to FDB of Next Extension      !
        !-------------------------------------------------!
        !  FBADR                                          !
 .FBADR !       Disk Address of File's Index Block        !
        !-------------------------------------------------!
        !  FBPRT                 !                        !
 .FBPRT !          500000        !    File Access Bits    !
        !-------------------------------------------------!
        !  FBCRE                                          !
 .FBCRE !       Date and Time of Last Write to File       !
        !-------------------------------------------------!
        !  FBAUT                                          !
 .FBAUT !            Pointer to Author String             !
        !-------------------------------------------------!
        !  FBGEN                 !FBDRN                   !
 .FBGEN !     Generation Number  ! Dir.# (if a DIR File)  !
        !-------------------------------------------------!
                                                     Page 79


        !  FBACT                                          !
        !           500000,,0 %+ Account Number           !
        !                       or                        !
 .FBACT !            Pointer to Account String            !
        !-------------------------------------------------!
        !0     5!6    11!  !14 17!18                    35!
        ! FBGNR ! FBBSZ !  !FBMOD!  FBNPG                 !
 .FBBYV !# Gens.!Byte Sz!  ! Mode!  # of Pages in File    !
        !-------------------------------------------------!
        !  FBSIZ                                          !
 .FBSIZ !               # of Bytes in File                !
        !-------------------------------------------------!
        !  FBCRV                                          !
 .FBCRV !            Date and Time of Creation            !
        !-------------------------------------------------!
        !  FBWRT                                          !
 .FBWRT !        Date and Time of Last User Write         !
        !-------------------------------------------------!
        !  FBREF                                          !
 .FBREF !      Date and Time of Last Nonwrite Access      !
        !-------------------------------------------------!
        !  FBNWR                 !  FBNRF                 !
 .FBCNT !       # of Writes      !     # of References    !
        !-------------------------------------------------!
|       !  FBBK0                                          !
|.FBBK0 !                 Backup Word #1                  !
        !-------------------------------------------------!
        !  FBBK1                                          !
 .FBBK1 !                 Backup Word #2                  !
        !-------------------------------------------------!
        !  FBBK2                                          !
 .FBBK2 !                 Backup Word #3                  !
        !-------------------------------------------------!
|       !  FBBBT                 !                        !
|.FBBBT !            Flags       ! # of pages when deleted!
        !-------------------------------------------------!
|       !  FBNET                                          !
|.FBNET !          Date and time of on-line expiration    !
        !-------------------------------------------------!
        !  FBUSW                                          !
 .FBUSW !               User Settable Word                !
        !-------------------------------------------------!
        !  FBGNL                                          !
 .FBGNL !         Link to FDB of Next Generation          !
        !-------------------------------------------------!
                                                     Page 80


        !  FBNAM                                          !
 .FBNAM !           Pointer to File Name Block            !
        !-------------------------------------------------!
        !  FBEXT                                          !
 .FBEXT !           Pointer to Extension Block            !
        !-------------------------------------------------!
        !                                                 !
 .FBLWR !          Pointer to Last Writer String          !
        !                                                 !
        !-------------------------------------------------!
|       !  FBTDT                                          !
|.FBTDT !  Date and time of archive/collection tape write !
        !-------------------------------------------------!
|       !  FBFET                                          !
|.FBFET !       Date and time of off-line expiration      !
        !-------------------------------------------------!
|       !  ARTP1                                          !
|.FBTP1 !       Tape ID for first archive/collection run  !
        !-------------------------------------------------!
|       !  TFN1                  ! TSN1                   !
|.FBSS1 !  Saveset # for 1st tape! Tape file # in saveset !
        !-------------------------------------------------!
|       !  ARTP2                                          !
|.FBTP2 !      Tape ID for second archive/collection run  !
        !-------------------------------------------------!
|       !  TFN2                  ! TSN2                   !
|.FBSS2 ! Saveset # for 2nd tape ! Tape file # in saveset !
        +-------------------------------------------------+



                           1 1 1 1 1  1 1                 3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4  7 8                 5
      +-----------------------------------------//---------+
.FBCTL! ! ! ! ! ! ! ! ! ! ! ! ! ! !    !                   !
      +-----------------------------------------//---------+


   Symbol     Bits      Contents

   FB%TMP       0       File is temporary
   FB%PRM       1       File is permanent
   FB%NEX       2       On; no extension for this file 
                         Off; file does not really exist
   FB%DEL       3       File is deleted
                                                     Page 81


   FB%NXF       4       File does not exist (first 
                         write not complete)
   FB%LNG       5       Long file
   FB%SHT       6       Reserved for DEC
   FB%DIR       7       File is a directory
   FB%NOD       8       File is not saved by backup system
   FB%BAT       9       File may have bad pages
   FB%SDR      10       This directory has subdirectories
|  FB%ARC      11       File has archive status
|  FB%INV      12       File is invisible
|  FB%OFF      13       File is off-line
   FB%FCF    14-17      File class field
                          0 = .FBNRM  Not an RMS file
                          1 = .FBRMS  RMS file


                                1 1 1                     3
       0 1 2 3 4 5 6 7 8        5 7 8                     5
      +-------------------------------------//-------------+
.FBBBT! ! ! ! ! ! ! ! ! !      !   !                       !
      +-------------------------------------//-------------+


   Symbol     Bits       Contents

|  AR%RAR      1         Request for file to be archived
|  AR%RIV      2         System request for migration
|  AR%NDL      3         Do not delete disk contents 
|                         after archiving
|  AR%NAR      4         Resist migration
|  AR%EXM      5         File is exempt from migration
|  AR%1ST      6         First pass is in progress
|  AR%RFL      7         Restore failed
|  AR%WRN      8         User warned of file expiration
|  AR%RSM    15-17       Reason file pushed off-line:
|                         1 = .AREXP  File expired
|                         2 = .ARARR  Archive requested
|                         3 = .ARRIR  Migration requested
|  AR%PSZ    18-35       # of pages in file when removed 
|                         from disk
                                                     Page 82


     NOTE:  FBBK0 is used by DUMPER as follows:


                               1 1                        3
        0 1                    7 8                        5
       +---------------------------------------------------+
.FBBK0 ! !                      !                          !
       +---------------------------------------------------+


     Bits         Contents

      0           Indicator for interrupted incremental 
                   save
|     1-17        Count of incremental saves since last 
|                  time write count changed
     18-35        Write count at last incremental save
                                                     Page 83


                      FE-STORAGE-AREA

Front End Storage  Area.   Each  entry  is  FEN  words  long
(except  FEUNVW),  where  FEN equals the number of front end
devices.

Defined in:  STG

Referenced by:  FESRV

                                Format

        +-------------------------------------------------------+
        \         |       |  FEFEM  |  FEFRK                    |
FEUDB0: \  Flags  |       | FE Alloc|   Fork # Owning Device    \
        +-------------------------------------------------------+
        |  FEICT          |  FEICM           |  FEFEI           \
FEUDB1: |  Current Input  |  Maximum Input   | Bytes Now in FE  |
        |   Byte Count    |    Byte Count    |                  |
        |-------------------------------------------------------|
        \  FEIPT                                                \
FEUDB2: \                  Input Byte Pointer                   \
        |-------------------------------------------------------|
        \  FEIBF                    |  FEOBF                    \
FEUDB3: \   Input Buffer Address    |   Output Buffer Address   \
        |-------------------------------------------------------|
        \                                                       \
FEUDB4: |                  Input Input Pointer                  |
        |-------------------------------------------------------|
        |0   2|                                                 |
FEUNVW: |# FEs|               Input Input Pointer               |
        +-------------------------------------------------------+

        The buffer area for the front end is in the monitor's 
        nonresident address space.


        +-------------------------------------------------------+
FEBUFF  \                 1 Page in Length                      \
        +-------------------------------------------------------+




         0 1 2 3 4 5      12       17
        +-------------------------------------------------------+
FEUDB0: |   | | | | |      | FEFEM  |   FEFRK                   |
        |   | | | | |      |FE Alloc|    Fork # Owning Device   |
        +-------------------------------------------------------+


                Bit(s)     Pointer     Content

                 0%-1       FEDTE       DTE owning this device
                  2        FEBLK       Unit is blocked
                                                     Page 84


                  3        FEPST       Waiting for DTE Post
                  4        FEEOF       Input EOF declared by FE
                  5        FEVDT       FE assignment is valid
                12%-17      FEFEM       FE Allocation
                18%-35      FEFRK       Fork # owning device
                                                     Page 85


                           FKBSPW

This resident table contains pointers that comprise a linked
list  of  the  current  balance  set  members.   The initial
pointer to this list is BSLST.  The list is used  by  AJBALS
to  determine  the  status  of  the  current  members of the
balance set.  Note that an  entry  may  contain  a  non-zero
value  without  being  a  balance  set member.  Only entries
found by following the BSLST link are considered.  If a fork
is  placed on the balance set without hold time, it will not
appear on this list.

Defined in:  STG

Referenced by:  SCHED

Index:  Fork number

                                 Format

        +-------------------------------------------------------+
FKBSPW: |          Not used         | Balance set list pointer  | / \
        +-------------------------------------------------------+  |
        |                           .                           |  |
        |                           .                           | NFKS
        \                           .                           \  |
        |                           .                           |  |
        |                           .                           | \ /
        +-------------------------------------------------------+
                                                     Page 86


                           FKCNO

Fork Core Number Table.  This table contains the core number
(given when a process enters the balance set) for each fork.
The core number is used to set a corresponding  bit  in  the
pager's  process  use register (PUR) when the fork is chosen
to run.  

The left half of this table is used to hold  the  SPT  index
for  the  second  page of each fork's PSB table.  (see FKPGS
table for SPT index for first page of each fork's PSB).

Defined in:  STG, PROLOG

Referenced by:  PAGEM, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
  FKCNO:|  FSSPTN/HWPTN             |        Core Number        |  / \
        | SPTn for 2nd pg of PSB    |                           |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 87


                           FKINT

Fork   Interrupt   Table.    This   table    contains    the
pseudo-interrupt  communication register for each fork.  The
left half of each entry contains bits recording the type  of
request.  The symbols for these requests have right half bit
assignments (i.e.  bits 20-31) but are  tested  against  the
left half of the table.

Defined in:  STG

Referenced by:  FORK, MEXEC, NETWRK, PAGEM, SCHED, TTYSRV

Index:  Fork number

                                Format

         0                         18 19         26 27        35
        +-------------------------------------------------------+
FKINT:  |           Bits             | Unused      | JRMCOD     |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 88


Symbol       Bit   Pointer        Content

               0             Interrupt Request(s) pending
               1             Fork not interruptable
NEWFKF(B20)    2             Initiate new fork
NEWJBF(1B21)   3             Initiate new job
PSIIF(1B22)    4             Channel interrupt requested
                             in FKINTB
PSIT1F(1B23)   5             Terminal code Interrupt, Phase 1
PSIT2F(1B24)   6             Terminal code Interrupt, Phase 2
SUSFKR(1B25    7             Suspend fork request
PSIWTF(1B26)   8             Job was in wait state
PSILOB(1B27)   9             Logout job request
FRZB1(1B28)   10             Direct freeze has been done
FRZB2(1B29)   11             Indirect freeze has been done
PSICOB(1B30)  12             Carrier off action request
PSITLE(1B31)  13             Time Limit Exceeded interrupt
PSIJTR(1B32)  14             JSYS trap request
JTFRZB(1B33)  15             JSYS trap freeze
ADRBKF(1B34)  16             Address Break Request
ABFRZB(1B35)  17             Address Break Freeze
PSIPRI        18             Priority Word Set
UNUSED       19-26           Unused
             27-35           Field for terminal
                                                     Page 89


                           FKINTB

Fork Interrupt Buffer Table.  This table contains the buffer
for  the  pseudo-interrupt channel requests pending for each
fork since the fork's last PSI interrupt.

Defined in:  STG

Referenced by:  FORK, SCHED

Index:  Fork number

                                Format


        +-------------------------------------------------------+
FKINTB: |           Interrupt Channel Request(s)  Pending       |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 90


                           FKJOB

Fork Job Table.  This table holds each fork's job number and
JSB address (SPT index).

Defined in:  STG

Referenced by:  APRSRV, CDRSRV, DIAG, DTESRV,  ENQ,  FILMSC,
                FORK,  IPCF,  LINEPR,  MEXEC, NSPSRV, PAGEM,
                PHYSIO, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
        |  FKJOBN                   |  FKJSB                    |  / \
FKJOB:  |        Job Number         |      JSB (SPT Index)      |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 91


                           FKJTQ

Fork JSYS Trap Queue.  This doubly linked  list  is  a  JSYS
Traps  Queue  of forks waiting to program software interrupt
(PSI) the monitor.  JTLST points to  the  top  fork  on  the
linked JSYS traps queue in FKJTQ.

When a fork tries JTLOCK (in the JSB) and  some  other  fork
has  the lock, the fork is added to FKJTQ and blocked.  When
the lock is cleared, the queue is scanned for the first fork
(if any) waiting on the lock.  That fork is removed from the
queue and allowed to run.

Defined in:  STG
 
Referenced by:  SCHED

                                 Format

        +-------------------------------------------------------+
FKJTQ:  |  Ptr. to Previous Entry   |    Ptr. to Next Entry     |  / \
        |-------------------------------------------------------|   |
        |                                                       |   |
        |                                                       |   |
        |                                                       |
        |                                                       | NFKS
        |                                                       |
        |                                                       |   |
        \                                                       \  \ /
        +-------------------------------------------------------+
                                                     Page 92


                           FKNBW

This resident table saves the time of start of a balance set
wait of a fork.

Defined in:  STG

Referenced by:  SCHED

Index:  Fork number

                                 Format

        +-------------------------------------------------------+
FKNBW:  |             Time of start of BALSET wait              | / \
        +-------------------------------------------------------+  |
        |                           .                           |  |
        |                           .                           | NFKS
        \                           .                           \  |
        |                           .                           |  |
        |                           .                           | \ /
        +-------------------------------------------------------+
                                                     Page 93


                            FKNR

Fork Number of Reserve Pages Table.  This table contains  in
the right half the current reserve working set size for each
fork.  Also, it contains in the left half  the  current  age
stamp  (to  be loaded into the pager's age resister when the
fork is chosen to run) and the age stamp value at  the  last
time  local  garbage  collection (removal of less frequently
used pages) took place for the fork.

Defined in:  STG

Referenced by:  PAGEM, SCHED

Index:  Fork number

                                Format

         0           8 9          17 18                       35
        +-------------------------------------------------------+
        |  FKXAGE     |  FKAGE      |  FKWSS                    |  / \
FKNR:   |Age -Last XGC| Current Age | Reserve Working Set Size  |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 94


                           FKPGS

Fork Page and Process Storage Table.   This  table  contains
the  page  table  and  PSB  locations (SPT indexes) for each
fork.

Defined in:  STG

Referenced by:  DIAG, FORK, JSYSA, PAGEM, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
        |  FKUPT                    |  FKPSB                    |  / \
FKPGS:  |  Page Table (SPT Index)   |      PSB (SPT Index) *    |   |
        |                           |   for 1st page of PSB     |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+


        *   See FKCNO table description for SPT index for second
            page of PSB.
                                                     Page 95


                           FKPGST

Fork BALSET Wait Satisfied Test  Table.   This  table  holds
test  routine  information  for  forks in a balance set wait
state.  The  test  routine  checks  if  wait  satisfied  has
occurred.

For forks on a wait list (and therefore not in  the  balance
set),  this  table contains the time of day the fork entered
the list.  

Defined in:  STG

Referenced by:  SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+  / \
        |                           |     Test Routine for      |   |
FKPGST: |         Test Data         |   BALSET Wait Satisfied   |   |
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |-------------------------------------------------------|   |
        |            Time of Day Entered a Wait List            |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                     Page 96


                            FKPT

Fork List Pointer Table.  This  table  gives  the  chain  of
forks  for  each  list  of forks in the system.  That is, it
holds the linked list of forks  on  TTILST,  CLKLST,  GOLST,
etc.   A  fork  is  either  on  one of the wait-lists or the
go-list.

The right half contains the list pointer to the next fork on
the same list and the left half contains WTLST or GOLST.  If
the left half contains WTLST, the type of wait-list  can  be
obtained from the right half of FKQ2.

Defined in:  STG

Referenced by:  APRSRV, FORK, MEXEC, PAGEM, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
        | FKBET                     |                           |  / \
FKPT:   |Current Location (GOLST/   |       List Pointer        |   |
        |WTLST) or 400000 if fork   |                           |   |
        | free                      |                           |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                     Page 97


                            FKQ1

Fork Run Queue Table 1.  This  table  contains  each  fork's
remaining  run  quantum.   When  this  quantum  expires, the
process will be requeued to a lower run position  and  given
the the quantum associated with that run queue.

Defined in:  STG

Referenced by:  SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
FKQ1:   |  FKQTM                                                |  / \
        |             Fork's Remaining Run Quantum              |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                     Page 98


                            FKQ2

Fork Run Queue Table 2.  This table contains the queue level
number and fork location [i.e., list address (TTILST, GOLST,
etc.) for each fork.

Defined in:  STG

Referenced by:  FORK, NSPSRV, SCHED

Index:  Fork number

                                Format

         0  1  2   5 6    11 12   17 18                       35
        +-------------------------------------------------------+  / \
  FKQ2: |  |  |     |       |       |                           |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+


               Bits      Pointer    Content

                0        FKNTC      Network topology change 
                                     interrupt enabled
                1        PIBMP      PI boost flag
               2-5       FKFLG      Fork flags
               6-11      FKMXQ      Max Q for fork
              12-17      FKQN       Queue level number
              18-35      FKWTL      Wait list address for blocked fork
                                                     Page 99


                           FKSTAT

Fork Status Table.  This table has useful information when a
fork  blocks  and leaves the GOLST (i.e., LH (FKPT) contains
the list address, WTLST).

The blocked fork's entry in  this  table  will  contain  the
address  of  the test routine which, when called, determines
if wait satisfied has occurred for the fork.

Defined in:  STG

Referenced by:  DIRECT, FORK, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
FKSTAT: |         Test Data         |   Test Routine Address    |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                    Page 100


                           FKSWP

This resident table contains fork information that  is  used
primarily by the working set manager in its decisions.

Defined in:  STG, PROLOG

Referenced by:  FORK, PAGEM, SCHED

Index:  Fork number

                                 Format

        +-------------------------------------------------------+
FKSWP:  |   flags   |    FKGOLN     |           FKHST           | / \
        +-------------------------------------------------------+  |
        |                           .                           |  |
        |                           .                           | NFKS
        \                           .                           \  |
        |                           .                           |  |
        |                           .                           | \ /
        +-------------------------------------------------------+


         0 1 2 3 4 5 6 7 8        17 18                       35
        +-------------------------------------------------------+
        | | | | | | | | |  FKGOLN   |           FKHST           |
        +-------------------------------------------------------+

                  Bits      Pointer     Content

                   0        FKWSL       Working set loaded
                   1        FKBLK       Fork blocked off if on GOLST
                   2        FKIBS       Fork in balance set
                   3        BSWTB       Fork in balance set wait
                   4        BSNSK       NOSKED--on if fork is NOSKED
                                        and not running
                   5        BSCRSK      CRSKED--on if fork is CRSKED
                                        and not running
                   6        FKIBH       In balance set hold--on if fork
                                        entered balance set since last
                                        update to history
                   7        FKBSHF      In balance set hold in AJBALS
                                        algorithm
                  8-17      FKGOLN      GOLIST position
                 18-35      FKHST       Fork history
                                                    Page 101


                           FKTIME

Fork Time Table.  This table, indexed by fork  ,  gives  the
time  of  day  (TODCLK)  at  which  each fork was put on its
current run queue.

Defined in:  STG

Referenced by:  SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
FKTIME: |            Time When Fork Put on Run Queue            |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                    Page 102


                           FKWSP

Fork  Working  Set  (In%-Memory  Size)  Table.   This  table
contains  in  the  right  half  the number of physical pages
currently assigned to each fork.  The left half is  used  to
hold  the  preload  size  as determined by LDJOB when a fork
enters the balance set.

Defined In:  STG

Referenced by:  PAGEM, SCHED

Index:  Fork number

                                Format

        +-------------------------------------------------------+
        | FKNWCE                    |  FKCSIZ                   |  / \
FKWSP:  | # of entries in W.S. Cache|       Current Size        |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NFKS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \  \ /
        +-------------------------------------------------------+
                                                    Page 103


                           GTOKPR

This table is used by the access control code.  It  contains
one entry for each legal GETOK/GIVOK function.

Defined in:  STG

Referenced by:  ENQ, FORK, JSYSA, JSYSF, MEXEC, MSTR, SCHED,
TAPE, TTYSRV

                                 Format

        +-------------------------------------------------------+
GTOKPR: |                DGOUSR -- User requests                | / \
        +-------------------------------------------------------+  |
        |                DGOASD -- Assign device                |  |
        +-------------------------------------------------------+  |
        |         DGOCAP -- Enable/disable capabilities         |  |
        +-------------------------------------------------------+  |
        |                 DGOCJB -- Create job                  |  |
        +-------------------------------------------------------+  |
        |                    DGOLOG -- Login                    |  |
        +-------------------------------------------------------+  |
        |                 DGOCFK -- Create fork                 |  |
        +-------------------------------------------------------+  |
        |           DGOTBR -- Set terminal baud rate            |  |
        +-------------------------------------------------------+  |
        |                   DGOLGO -- Logout                    |  |
        +-------------------------------------------------------+  |
        |              DGOENQ -- ENQ quota setting              | MXGOKF
        +-------------------------------------------------------+  |
        |           DGOCRD -- Create/modify directory           |  |
        +-------------------------------------------------------+  |
        |               DGOSMT -- Structure mount               |  |
        +-------------------------------------------------------+  |
        |                 DGOMDD -- Enter MDDT                  |  |
        +-------------------------------------------------------+  |
        |              DGOCLS -- Set class for job              |  |
        +-------------------------------------------------------+  |
        |             DGOCL0 -- Set class at login              |  |
        +-------------------------------------------------------+  |
        |                  DGOMTA -- MT access                  |  |
        +-------------------------------------------------------+  |
        |                 DGOACC -- ACESS JSYS                  |  |
        +-------------------------------------------------------+  |
        |           DGOOAD -- Assign device via OPENF           | \ /
        +-------------------------------------------------------+
                                                    Page 104


                            HOM

Home Block.  Block on each disk unit  which  contains  vital
statistics  that  cannot  be  built  in  when  a  monitor is
generated.  These are primarily parameters of the  unit  and
the STR to which it belongs.

Defined in:  DSKALC

Referenced in:  DSKALC, PHYSIO, JSYSA




          +-------------------------------------------------------+
HOMNAM=0  |                      SIXBIT/HOM/                      |
          |-------------------------------------------------------|
HOMID=1   |                    SIXBIT/Unit ID/                    |
          |-------------------------------------------------------|
          |   Physical Disk Address   |   Physical Disk Address   |
HOMPHY=2  |    of This Home Block     |    of Other Home Block    |
          |-------------------------------------------------------|
HOMSNM=3  |                SIXBIT/Structure Name/                 |
          |-------------------------------------------------------|
HOMLUN=4  |     # of Packs in STR     | Logical Pack # Within STR |
          |-------------------------------------------------------|
          |        Block # of         |        Block # of         |
HOMHOM=5  |      This Home Block      |     Other Home Block      |
          |-------------------------------------------------------|
HOMP4S=6  |       # of Pages for Swapping on This Structure       |
          |-------------------------------------------------------|
HOMFST=7  |             First Swapping Track on Unit              |
          |-------------------------------------------------------|
HOMRXB=10 |       Address of Index Block of ROOT-DIRECTORY        |
          |-------------------------------------------------------|
          |               Address of Index Block of               |
HOMBXB=11 |             BACKUP-COPY-OF-ROOT-DIRECTORY             |
          |-------------------------------------------------------|
HOMFLG=12 |                         Flags                         |
          |-------------------------------------------------------|
HOMSIZ=13 |            Number of Sectors in This Unit             |
          |-------------------------------------------------------|
HOMBTB=14 |             Number of Tracks in Structure             |
          |-------------------------------------------------------|
HOMMID=15 |                   Pack Unique Code                    |
          |-------------------------------------------------------|
          |                                                       |
          \                    Reserved for Expansion             \
          |                                                       |
          |                                                       |
          |-------------------------------------------------------|
HOMFE0=61 |           Front End File System (sector #)            |
          |-------------------------------------------------------|
HOMFE1=62 |         Front End File System (# of sectors)          |
          |-------------------------------------------------------|
                                                    Page 105


          |                                                       |
          |                                                       |
          \                Reserved for the Front End             \
          |                                                       |
          |                                                       |
          |-------------------------------------------------------|
HOMFE2=101|        BOOTSTRAP.BIN Word One (Sector #)              |
          |-------------------------------------------------------|
HOMFE3=102|        BOOTSTRAP.BIN Word Two (# of Sectors)          |
          |-------------------------------------------------------|
          |                                                       |
          \                Reserved for Expansion                 \
          |                                                       |
          |                                                       |
          |-------------------------------------------------------|
HOMUID=165\    12 Character Unit I.D. (PDP-11 Format) (3 words)   \
          |-------------------------------------------------------|
HOMOID=170\    12 Character Owner I.D. (PDP-11 Format) (3 words)  \
          |-------------------------------------------------------|
HOMFSN=173\ 12 Character File System Name (PDP-11 Format)(3 words)\
          |-------------------------------------------------------|
HOMCOD=176|             0             |      CODHOM  (707070)     |
          |-------------------------------------------------------|
HOMSLF=177|             0             |       This Block #        |
          +-------------------------------------------------------+
                                                    Page 106


                            HOME

Home Table.  This table contains the disk pages for the HOME
and BAT blocks and the 11 Bootstrap program.

Defined in:  STG

Referenced by:  DSKALC


                                Format

        +-------------------------------------------------------+ / \
HOME:   |                    0 (11 Bootstrap)                   |  |
        |-------------------------------------------------------|  |
        |                    1 (Home Block )                    |  |
        |-------------------------------------------------------|  |
        |                    2 ( BAT Block )                    |  |
        |-------------------------------------------------------|  |
        |                    3  Reserved                        |  |
        |-------------------------------------------------------|  |
        |                    4      .                           |  |
        |-------------------------------------------------------|  |
        |                    5      .                           | 
        |-------------------------------------------------------| NHOME
        |                    6      .                           |
        |-------------------------------------------------------|  |
        |                    7      .                           |  |
        |-------------------------------------------------------|  |
        |                   10      .                           |  |
        |-------------------------------------------------------|  |
        |                   11      .                           |  |
        |-------------------------------------------------------|  |
        |                   12 (Secondary Home Block)           |  |
        |-------------------------------------------------------|  |
        |                   13 (Secondary Bat Block)            |  |
        +-------------------------------------------------------+ \ /
                                                    Page 107


                           HOMTAB

This table contains the logical to physical mapping (channel
and  unit)  per  logical  unit,  and  its  length equals the
maximum number of packs in a structure.

Defined in:  STG

Referenced by:  DSKALC

                                 Format

        +--------------------------------------------------------+
HOMTAB: |    Physical Channel       |        Physical Unit       |  / \
        |--------------------------------------------------------|   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |
        |                           .                            |  HOMTBL
        |                           .                            |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        |                           .                            |   |
        +--------------------------------------------------------+  \ /
                                                    Page 108


                           IDXFIL

The Index Table File of the structure currently mapped for a
process.   Each structure has an index table file.  The file
is indexed by 2* directory number as each entry is two words
long.   For  each  directory on the structure, an entry will
contain the address of the FDB for  the  directory  and  the
disk address of the index block for the directory.

The table, IDXFIL, in the PSB,  is  mapped  from  the  index
block of the file, STRNAM:  <ROOT-DIRECTORY>INDEX-TABLE.BIN.
The file pointed to by the IDXFIL map has the  format  shown
below.

When a structure is mounted (physically) the system gets  an
OFN for this file and stores it in entry, STRIDX, in the SDB
table for that structure.  The table entries are created  at
this time (mount-time).

Defined in:  PROLOG

Referenced in:  FILINI, DIRECT

                                  Format

           +-------------------------------------------------+
IDXFIL:    |                                                 |    / \
           |-------------------------------------------------|     |
           |                                                 |     |
           |-------------------------------------------------|     |
           |                        .                        |     |
           |                        .                        |     |
           |                        .                        |     |
           |-------------------------------------------------|
           | IDXSD                  | IDXFDB                 | Dir No.
           | Superior Dir.          | Adr. of FDB for        |*2
           |                        |    this Dir.           |     |
           |-------------------------------------------------|     |
           | IDXFG | IDXIB                                   |     |
           | Flags | Disk Adr of Index Blk of Dir.           |     |
           |-------------------------------------------------|     |
           |                        .                        |     |
           |                        .                        |     |
           |                        .                        |     |
           \                                                 \    \ /
           +-------------------------------------------------+
                                                    Page 109





     Word 2 of Pair

             0 1 2 3 4 5 6                          35
            +-----------------------------------------+
            |         | | IDXIB                       |
            |         | | Dsk Adr of Index Blk of Dir.|
            +-----------------------------------------+


          Symbol       Bits    Pointer      Meaning

          IDX%%IV        5                 If set, indicates that this
                                           IDX entry is invalid. 
                                           (IDX%IV is set equal to 1,
                                           but is positioned at bit 5)

                      6-35    IDXIB      Disk address of index block
                                           of directory.
                                                    Page 110


                           INDEX

The Index Block (1 page)  exists  for  each  disk  file  and
contains  pointers to where each of the file's pages resides
on disk.  If  more  than  one  index  block  is  needed  for
non%-directory  files,  a  super  index  block  (1  page) is
created which points to the home disk address of each  index
block.  (Note that the maximum file size is 512*512 pages.)

When the file is referenced, an in%-core copy of  the  index
block  is  maintained which keeps track of the file's active
pages in the system.  (i.e.  Whether the pages are in%-core,
on the swapping area, or on disk.)

Defined in:

Referenced by:  PAGEM, PHYSIO

                                  Format

              +-------------------------------------------+
              | 0          8|                             |
              | C           |       Storage Address       |
              |  H          |                             |
              |-------------------------------------------|
              | 0  E       8|                             |
              |     C       |       Storage Address       |
              |      K      |                             |
              |-------------------------------------------|
              | 0          8|                             |
              |       S     |        Storage Address      |
              |        U    |                             |
              |-------------------------------------------|
              | 0       M  8|                             |
              |             |        Storage Address      |
              |-------------------------------------------|
              |                                           |
              |                      Storage Address      |
              |                                           |
              |-------------------------------------------|
              |                            .              |
              |                            .              |
              |                            .              |
              |                                           |
              |                                           |
              |-------------------------------------------|
              |                                           |
              |                      Storage Address      |
              |                                           |
              +-------------------------------------------+
                                                    Page 111


                           INIDEV

Initialization Device Routines.  This table  contains  calls
to initialize devices after loading the swappable monitor.

Defined in:  STG

Referenced by:  FILINI


                                Format


        +-------------------------------------------------------+
INIDEV: |                     CALL MTAINI                       |
        |-------------------------------------------------------|
        |               CALL LPTINI (2020 only)                 |
        |-------------------------------------------------------|
        |                CALL CDPINI (KL only)                  |
        |-------------------------------------------------------|
        |                          RET                          |
        +-------------------------------------------------------+
                                                    Page 112


                           INIDV1

Front End Initialization Device Routines.

Defined in:  STG

Referenced by:  DTESRV


                                Format


        +-------------------------------------------------------+
INIDV1: |                 CALL FEINI (KL only)                  |
        |-------------------------------------------------------|
        |                       CALL CDRINI                     |
        |-------------------------------------------------------|
        |                CALL LPTINI (KL only)                  |
        |-------------------------------------------------------|
        |                          RET                          |
        +-------------------------------------------------------+
                                                    Page 113


                           INIDVT

Device Initialization Table.  This static table generated at
assembly  time,  contains  a  4  word block for each type of
device on the system.  It is used at system startup time  to
generate  unit     of  entries per device type in the device
tables, DEVCHR, DEVCH1, DEVNAM, DEVUNT.  Thus, each unit  of
each device type has an entry in the device tables.

Defined in:  STG, MONSYM

Referenced by:  DEVICE  


                                Format


        +-------------------------------------------------------+ / \
INIDVT: |                     SIXBIT/Name/                      |  |
        |-------------------------------------------------------|  |
        | Device Type Index # = 0   |     Dispatch Adr.         |  
        |-------------------------------------------------------|  4
        |      Char1|   <TYPE>B17   |          Modes            |  
        |-------------------------------------------------------|  |
        |            CHAR2 + CHAR3+ Number of Units             |  |
        |-------------------------------------------------------| \ /
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        \                           .                           \
        +-------------------------------------------------------+
                                                    Page 114



        
        CHAR1 can be a combination of the following:

                Symbol          Bit     Meaning

                DV%%OUT           0     Can do output
                DV%%IN            1     Can do input
                DV%%DIR           2     Has a directory
                DV%%AS            3     Is assignable
                DV%%MDD           4     Is a multiple directory device
                DV%%AV *          5     Is available to this job
                DV%%ASN *         6     Is assigned by ASND
                DV%%MDV           7     Is a mountable device
                DV%%MNT *         8     Is mounted


        TYPE is one of the following:

                Symbol         Value    Meaning

                .DVDSK           0      Disk
                .DVMTA           2      Magtape
                .DVPTP           5      Spooled PTP
                .DVLPT           7      Spooled & physical line printer
                .DVCDR          10      Spooled & physical card reader
                .DVFE           11      Front End Device
                .DVTTY          12      Terminal
                .DVPTY          13      Pseudo TTY
                .DVNUL          15      Null Device
                .DVPLT          17      Spooled Plotter
                .DVCDP          21      Spooled Card Punch

        MODES can be a combination of the following:

                Symbol          Bit     Meaning

                DV%%M0          35      Can be opened in mode 0
                DV%%M1          34              "             1
                DV%%M2          33              "             2
                DV%%M3          32              "             3
                DV%%M4          31              "             4
                DV%%M5          30              "             5
                DV%%M6          29              "             6
                DV%%M7          28              "             7
                DV%%M10         27              "            10
                DV%%M11         26              "            11
                DV%%M12         25              "            12
                DV%%M13         24              "            13
                DV%%M14         23              "            14
                DV%%M15         22              "            15
                DV%%M16         21              "            16
                DV%%M17         20              "            17
                                                    Page 115




        CHAR2 can be a combination of the following:

                Symbol          Bit     Meaning

                D1%%SPL           0     Is spooled
                D1%%ALC *         1     Is under control of allocator
                D1%%VVL *         2     Volume valid
                D1%%NIU *         3     Device slot not in use
                D1%%INI *         4     Device is being initialized
                                         (currently for structures only)


                *  These bits are zero at assembly time and are set
                   by the monitor when appropriate in their corres-
                   ponding device tables.  (i.e. DEVCHR or DEVCH1)
                                                    Page 116


                            IORB

I/O Request Block.  Whenever a request for massbus I/O (i.e.
DSK  or  MTA) occurs, an IORB is built for that request.  It
is of the long form described below for magtape requests and
special  disk I/O.  However, the most common IORB format for
disk I/O is a one word IORB, consisting of just  the  status
word, IRBSTS, and stored in the CST5 table.

Defined:  PHYPAR

Referenced by:  PHYSIO, STG



                                 Format

        +-------------------------------------------------------+
        |                           |IRLNK                      |*
IRBSTS=0|          Status           |         Next IORB         |0=IRBLNK
        |-------------------------------------------------------|
IRBMOD=1|            Mode, Priority, Density, Parity            |
        |-------------------------------------------------------|
IRBCNT=2|           Count of Hardware Bytes Transfered          |
        |-------------------------------------------------------|
        |  IRBTL                    |IRBHD                      |
IRBXFL=3|    Transfer List Tail     |    Transfer List Head     |
        |-------------------------------------------------------|
IRBIVA=4|            Address of Termination Routine             |
        |-------------------------------------------------------|
IRBADR=5|          Physical Device Address (if needed)          |
        |-------------------------------------------------------|
IRBLEN=6\                Device Dependent Data                  \
        |                                                       |
        +-------------------------------------------------------+
                                                    Page 117





       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 17 18                    35
      +-------------------------------------------------------------+
IRBSTS| | | | | | | | | | | | | | |        |                        |
      +-------------------------------------------------------------+


        Symbol   Bits  Pointer  Content
                
        IS.SHT     0            Short form (PAGEM) request
        IS.DON     1            Done with this job
        IS.ERR     2    ISERR   Error on this operation
        IS.NRT     3            No more retries
        IS.WGU     4            Wrong unit interrupted
        IS.TPM     5    ISTPM   Hit tape mark
        IS.EOT     6            On write only, hit physical EOT
        IS.WLK     7            Write locked
        IS.IER     8            Inhibit error recovery
        IS.DTE     9            Data error
        IS.DVE    10            Hardware error on device
        IS.BOT    11            Hit BOT
        IS.RTL    12            Record too long (buffer too small)
        IS.IEL    13            Inhibit error logging
                 14-17  IFSCN   Function code
                 18-35  IRLNK   When referring to link


                Function Codes for ISFCN

        Symbol    Code          Function

        IRFRED      1           Read data
        IRFRDF      2           Read data and format (count, key,
                                 header)
        IRFWRT      3           Write Data
        IRFWTF      4           Write format
        IRFSEK      5           Seek
        IRFFSB      6           Forward space block
        IRFBSB      7           Backspace block
        IRFWTM     10           Write tape mark
        IRFERG     11           Erase gap
        IRFREW     12           Rewind
        IRFRUN     13           Rewind and unload
        IRFRDR     14           Read reverse
        IRFRCR     15           Recovery read
                                                    Page 118





         0                14 5 6 17 18          26 7 8 9 0 1 32   35
        +-----------------------------------------------------------+
IRBMOD  |                   |      |              |       | |       |
        +-----------------------------------------------------------+


                Bits        Pointer     Content

                15%-17       IRBDM       Data Mode
                27%-30       IRBPRI      Priority
                31          IRBPAR      Parity
                32%-35       IRBDN       Density


                        Data Modes for IRBDM

                Symbol       Code       Meaning

                IRMWRD        1         Word mode
                IRM6BT        2         Six bit
                IRM7BT        3         Seven bit
                IRM8BT        4         Eight bit
                IRMHID        5         High density mode








   If device is DSK, IRBLEN becomes:

        +-------------------------------------------------------+
IRBLEN  |                     Transfer List                     |
        |-------------------------------------------------------|
        |                           0                           |
        +-------------------------------------------------------+
                                                    Page 119





   If device is MTA, IRBLEN=MTIRSD becomes:

         0           8 9          17 18                       35
        +-------------------------------------------------------+
        | IRFLG      *| IRBUN       |IRBPB                      |
MTIRSD  |    Flags    |  Unit No.   |Ptr to Buffer of Page Ptrs |
        |-------------------------------------------------------|
        |                           | IRBOC                     |
        |                           |      Original Count       |
        |                           | (Copy of IRBCNT)          |
        |-------------------------------------------------------|
MTIRBL  |                     Transfer List                     |
        |_______________________________________________________|
        |                           .                           |
        \                           .                           \
        |                           .                           |
        |                           .                           |
        +-------------------------------------------------------+




Value of flags in IRFLG:


        Bits         Pointer      Content

          0          IRBFR        Buffer ready for use
          1          IRBFQ        Current buffer flag
          2          IRBFA        Active flag, IORB being filled
                                   or emptied by service routine
          3          IRBAB        IORB aborted due to an error
          4          IRBFF        IORB free
                                                    Page 120


                    IPCF-MESSAGE-HEADER

IPCF Message header.  This table describes the format of the
message   header  for  message  sent  by  the  Inter-Process
Communications Facility.

Defined in:  IPCF

Referenced by:  IPCF

                                   Format

          0                        17 18                       35
         +-------------------------------------------------------+
         |  MESLNK                   |  MESLEN                   |
       0 |   Link to Next Message    |   Length of This Block    |
         |-------------------------------------------------------|
       1 |  MESSJN                   |  MESFLG                   |
         |    Sender's Job Number    |           Flags           |
         |-------------------------------------------------------|
       2 |  MESSPD                                               |
         |                   Sender's      PID                   |
         |-------------------------------------------------------|
       3 |  MESLDN                                               |
         |            Logged in Directory # of Sender            |
         |-------------------------------------------------------|
       4 |  MESENB                                               |
         |            Enabled Capabilities of Sender             |
         |-------------------------------------------------------|
       5 |  MESCDN                                               |
         |            Connected Directory # of Sender            |
         |-------------------------------------------------------|
MESACT=6 |  MESACT                                               |
         \              Account String Block                     \
         |                                                       |

         |-------------------------------------------------------|
MESWDI=20|  MESWDO                                               |
         \                        Message                        \
         |                 (PTN.PN in Page Mode)                 |
         |-------------------------------------------------------|
MESWDI+1 |  MSFTM                                                |
         |             Mask into Fork Page Bit Table             |
         |                   (PAGE Mode only)                    |
         |-------------------------------------------------------|
MESWDI+2 |  MESPAC                  |  MSFTI                     |
         |        Access Bits       |        Index into          |
         |          of Page         |      Fork Bit Table        |
         +-------------------------------------------------------+
                                                    Page 121


                      IPCF-PID-HEADER

IPCF Process ID Header.  This contains overhead  information
for each PID in use.

Defined in:  IPCF

Referenced by:  IPCF

         0          8 9 11 12     17 18                       35
        +-------------------------------------------------------+
        | PIDUN                     |                           |
        |          Unique           |   Length of this block    |
        |        (LH of PID)        |                           |
        |-------------------------------------------------------|
        | PIDFLG*         | PIDCHN  | PIDFW                     |
        |    Flags        |    Chn  |      Fork Number of       |
        |                 |         |       Waiting Fork        |
        |-------------------------------------------------------|
        | PIDRQ       | PIDRC       | PIDFO                     |
        |  Receive    |  Receive    |      Fork Number of       |
        |  Quota      |  Count      |     Owner of this PID     |
        |-------------------------------------------------------|
        | PIDNL                     | PIDOL                     |
        |          Link to          |          Link to          |
        |      Newest Message       |      Oldest Message       |
        +-------------------------------------------------------+


         0                           18                       35
        +-------------------------------------------------------+
        |      ||||   |   PIDCHN    |           PIDFW           |
        |      ||||   |     CHN     |      Fork Number of       |
        |      ||||   |             |       Waiting Fork        |
        +-------------------------------------------------------+

       Symbol    Value          Contents

       PD%JWP      1            PID is a Job-wide PID
       PD%DIS      2            PID is disabled
       PD%CHN      4            channel is set up to
                                 get interrupts
       PD%NOA     10            access by other forks
                                                    Page 122


                     IPCF-STORAGE-AREA

Inter-Process Communication  Facility  Storage  Area.   This
non-resident  storage  is described followed by the resident
wake-up bit table (PDFKTB).  See also the tables, PIDCNT and
PIDTBL.

Defined in:  STG

Referenced by:  GTJFN, IPCF, LOGNAM, MEXEC

                                Format

        +-------------------------------------------------------+ / \
SPIDTB: |                                                       |  |
        \              Table of Commonly Used PIDS              \ SPDTBL=8
        \                                                       \  |
        |-------------------------------------------------------| \ /
PIDLOK: |       Lock on PID Free Pool and Data Structure        |
        |-------------------------------------------------------|
NXTPID: |         Next Unique # to be used as LH of PID         |
        |-------------------------------------------------------|
INFOPD: |                  PID of SYSTEM INFO                   |
        |-------------------------------------------------------|
INFOPV: |            Public Value of SYSTEM INFO PID            |
        |-------------------------------------------------------|
PIDLST: |          Number of First Free PID, 0 if none          |
        |-------------------------------------------------------|
PIDMXP: |         Highest Page in Pages-In-Transit File         |
        |-------------------------------------------------------| / \
PIDPBT: |                                                       |  |
        \          Bit Table of Pages-In-Transit File           \ PIDPBL
        \                                                       \  |
        |-------------------------------------------------------| \ /
PIDFTB: |                                                       | / \
        \       TBL of PTN's of forks for pages in transit      \  |
        \                                                       \ PIDFTL
        |                                                       |  |
        |-------------------------------------------------------| \ /
SWPFRE#:|                                                       | / \
        \           Free Space Header Block (7 words)           \  7
        \                                                       \  |
        |-------------------------------------------------------| \ /
SWFREE#:|                                                       | / \
        |                    Free Space Pool                    |  |
        |                (PID Headers & Messages                |  |
        |                 Assigned Space here)                  | SWFREL
        |                                                       |  |
        \                                                       \  |
        |-------------------------------------------------------| \ /
PIDCNT: |                                                       | / \
        \          Table of quotas and counts for IPCF          \  |
        \                                                       \ NJOBS
        +-------------------------------------------------------+ \ /
                                                    Page 123



        +-------------------------------------------------------+
PDFKTB  | | | | | . .                                           |
        |-------------------------------------------------------|
        \               Bit Wakeup Table (1/Fork)               \
        +-------------------------------------------------------+


    # See Swap%-Free%-Space%-Pool Table.
                                                    Page 124


                           JOBDIR

Job Directory Table.  This table contains the number of  the
login directory for each job.

Defined In:  STG

Referenced  by:  APRSRV,  CDRSRV,  DIRECT,   DISC,   DTESRV,
                FILINI,  FUTILI, IPCF, JSYSA, JSYSF, LINEPR,
                MAGTAP, MEXEC, MSTR, SCHED, TAPE, TTYSRV

                                Format

        +-------------------------------------------------------+  / \
JOBDIR: |        Reserved           |     Login Directory #     |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /
                                                    Page 125


                           JOBNAM

Job Name Table.  This  table  contains  an  index  into  the
subsystem name tables (SNAMES, STIMES, etc.) indicating what
subsystem, if any, each job is running.  The name  index  is
for statistics only and is not used by the monitor.

Defined In:  STG

Referenced by:  DIAG, FORK, MEXEC, PAGEM, SCHED

Index:  Job number

                                Format

        +-------------------------------------------------------+  / \
JOBNAM: |||                         |        Name Index         |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /


                Symbol     Bit      Pointer          Content

                JWAKEF      0       HIBFL         Flag used by HIBER JSYS.  
                                                   If set, implies a wakeup
                                                   signal to THIBR
                            1       DIAFL         Job has DIAG resources
                           1-2      SKPCT         Skip count for NEWUTL
                          18-35                   Name index
                                                    Page 126


                           JOBPNM

Job Program Name.  This  non-resident  table  contains  each
job's program name.

Defined In:  STG

Referenced by:  CDRSRV, DTESRV, IPCF, JSYSA, LINEPR,  MAGTAP,
                MEXEC

Index:  Job number

                                Format

        +-------------------------------------------------------+  / \
JOBPNM  |                    Job Program Name                   |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /
                                                    Page 127


                           JOBPT

Job Process Table.  This table, contains the number  of  the
controlling  terminal,  or  -1  for  a detached job, and the
index of the top fork of the job.

Defined in:  STG

Referenced by:  DEVICE, DIAG, FILMSC, FORK, IO, IPCF, JSYSA,
                MEXEC, MSTR, SCHED, TTYSRV


                                Format


        +-------------------------------------------------------+  / \
JOBPT   |   Controlling Terminal    |      Top Fork Index       |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /
                                                    Page 128


                           JOBRT

Job Runtime Table.  This table contains the total runtime of
each  job  (sum  of  all  forks) in milliseconds.  If a word
contains a -1, the job does not exist.

Defined in:  STG

Referenced by:  ENQ, FORK, FUTILI, IPCF, JSYSA, MEXEC, MSTR,
                SCHED

Index:  Job number

                                Format

        +-------------------------------------------------------+  / \
JOBRT:  |                        Runtime                        |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /
                                                    Page 129


                           JOBRTL

Job Runtime Limit.  This table contains the number of clocks
(via  TIMER  JSYS)  in  use by each job and a pointer to the
runtime limit TIMER block.  A description of the TIMER block
is described below.  (See RES-FREE-SPACE).

Defined in:  STG, PROLOG

Referenced by:  MEXEC, SCHED, TIMER

Index:  Job number

                                Format

         0            12 13        
        +-------------------------------------------------------+ 
        | TIMCNT        | JOBRTP                                |  / \
JOBRTL: | # of Clks. in |         Ptr to  Runtime Limit Block   |   |
        |  Use          |                                       |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NJOBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        +-------------------------------------------------------+  \ /



                TIMER Run Timer Limit Block

                +---------------------------------------+
                | TIMLNK                                |
                |   Link to Next Block (Q)              |
                |---------------------------------------|
                | TIMTIM                                |
                |   Time Word (When Clock Should Go Off |
                |---------------------------------------|
                |0      5|6        17|18              35|
                | TIMCHN | TIMJOB    | TIMFRK           |
                |        |Job # that | Sys. Fork Handle |
                |        |Set Clock  | to be PSI'd      |
                |---------------------------------------|
                | TIMKNL                                |
                |   Back Link to Previous Clock         |
                +---------------------------------------+       
                                                    Page 130


                            JSB

Job Storage Block.  Each job has a Job Storage  Block  which
holds  per-job information such as the job's fork structure,
line number of controlling TTY, terminal interrupts  enabled
and accounting and logical name information.

The JOBMAP map in the JSB  points  to  all  of  the  per-job
storage  (including  the JSB page itself).  When the monitor
references this current job's storage area it  uses  virtual
addresses  620000-706777.   (The  monitor's  mapped slots in
MMAP for virtual pages 620-706 point to the JOBMAP  map  via
indirect pointers.)

JBCOR contains a bit table which keeps track of which  pages
in  the  Job  Storage Area are in use (bit(s) = 0) and which
are free (bit(s) = 1).  The first several pages of this  Job
Common  Area  will always be allocated for the JSB page plus
expansion pages for the JFN blocks and  for  the  JSYS  trap
header  word  and  trap blocks (See FKJTQ table).  The first
non-reserved page begins at FREJPA (=626000).

JSBFRE is the free block header.  If a block of words (i.e.,
<512  words)  is  required,  it is allocated from the JSFREE
area in the JSB.  Blocks in the JSFREE area are  linked  and
when  a  block of words is required, the free list is search
looking for a large enough block.  If the free list area  in
JSFREE is depleted, a new page (space outside the JSB in the
Job Storage Area) is allocated and its space  added  to  the
free list for block usage.

Pages are  assigned  from  the  bit  table,  JBCOR,  by  the
routine,  ASGPAG,  and are used for temporary job pages such
as file window pages, magtape buffer pages, mapping a  super
index  block,  getting more space for the free block storage
linked in JSBFRE, and mapping EXE file directory pages.

Blocks of words are assigned from the free list,  headed  by
JSBFRE  by  the  routine,  ASGFRE,  and  are  used  to  hold
temporary storage such as name strings for JFN  blocks,  the
job-wide Logical Names List, and the Logical Name Definition
Blocks.

Defined in:  STG

Referenced by:  PAGEM, SCHED, FORK, POSTLD, PROLOG,  DSKALC,
                DISC, JSYSA, JSYSF, FILINI, FREE, GTJFN, IO,
                IPCF, LOGNAM, MAGTAP, MEXEC,  MSTR,  NETWRK,
                NSPSRV, TAPE
                                                    Page 131



                                Format

        +-------------------------------------------------------+
JSBPGA: |                                                       |
JOBMAP: |            Object Map for Job-Common Area             |
        |                                                       |
        \                                                       \
        \                                                       \
        |                                                       |
        |                                                       |
        |-------------------------------------------------------|*/ \
SYSFK:  |       Job Fork Index to System Fork Index Table       |  |
        \                   (1 Entry /Job Fork)                 \ NUFKS
        |                                                       |  |
        |-------------------------------------------------------| \ /
FKCTTY: |    Job Fork 0 Ptr         |   Job Fork 1 Ptr          | / \
        |-------------------------------------------------------|  |
        \            .                          .               \ NUFKS
        \            .                          .               \  2
        |            .                          .               |  |
        |-------------------------------------------------------| \ /
FKJTB:  |               Adr of JSYS Trap Block                  | / \
        |                   (1 Entry /Job Fork)                 |  |
        \                           .                           \ NUFKS
        |                           .                           |  |
        |-------------------------------------------------------| \ /
FKPTRS: |            Fork Pointers (Structure) Table            | / \
        \                   (1 Entry /Job Fork)                 \ NUFKS
        |                                                       |  |
        |-------------------------------------------------------| \ /
FKPSIE: |         Terminal Interrupt Enabled Word Table         | / \
        \                   (1 Entry /Job Fork)                 \ NUFKS
        |                                                       |  |
        |-------------------------------------------------------| \ /
FKDPSI: |        Deferred Terminal Interrupts Mask Table        | / \
        \                   (1 Entry /Job Fork)                 \ NUFKS
        |                                                       |  |
        |-------------------------------------------------------| \ /
FREJFK: |                Free Job Fork Slot List                |
        |-------------------------------------------------------|
FKLOCK: |         Lock for Fork Structure Modification          |
        |-------------------------------------------------------|
FLKCNT: |               Nest Count for Fork Lock                |
        |-------------------------------------------------------|
FLKOWN: |             Fork That Locked Fork Lock                |
        |-------------------------------------------------------|
FLCNT:  |          Count of Active Forks in This Job            |
        |-------------------------------------------------------|
LSTLGN: |               Last LOGIN Date and Time                |
        |-------------------------------------------------------|
SRTTIM: |            Data & Time Job Was Initialized            |
        |-------------------------------------------------------|
ARDFRT: |              Job Default for Retrievals               |
        |-------------------------------------------------------|
                                                    Page 132


CTRLTT: |            Line Number of Controlling TTY             |
        |-------------------------------------------------------|
TTSPSI: |           Code Enabled Anywhere in This Job           |
        |-------------------------------------------------------|
TTSDPS: |           Terminal Interrupt Code Deferred            |
        |-------------------------------------------------------|
TTJTIW: |            Terminal Interrupt Enable Mask             |
        |-------------------------------------------------------|
CONSTO: |             Console Time On (TODCLK units)            |
        |-------------------------------------------------------|
CTIMON: |                 Connect Time On (GTAD units)          | 
        |-------------------------------------------------------|
CONCON: |              Console Connect Time (for usage)         |
        |-------------------------------------------------------|
JBRUNT: |                 Job Run Time (for usage)              |
        |-------------------------------------------------------|
JBNODE: |                     Node Name (SIXBIT)                |
        |-------------------------------------------------------|
JBBNAM: |                 Batch Job Name (SIXBIT)               |
        |-------------------------------------------------------|
JBBSEQ: |                  Batch Sequence Number                |
        |-------------------------------------------------------|
ACCTSL: |                   Length of ACCTSR                    |
        |-------------------------------------------------------| / \
ACCTSR: \                    Account String                     \ MAXLW
        |-------------------------------------------------------| \ /
ACCTSX: |                 Expiration Data of ACCTSR             |
        |-------------------------------------------------------| / \
CSHACT: \           Most recently Validated Account             \ MAXLW
        |-------------------------------------------------------| \ /
CSHUSR: |      User for Whom Cached Account was Validated       |
        |-------------------------------------------------------|
CSHACX: |              CSHACT Expiration Date                   |
        |-------------------------------------------------------|
CSHCLS: |              Class of Cached Account                  |
        |-------------------------------------------------------|
LLSR:   |                  Logical Location                     |
        |-------------------------------------------------------| / \
JSSRM:  \                    Session Remark                     \ MAXLW+1
        |-------------------------------------------------------| \ /
        |                                                       | / \
USRNAM: \                   User Name String                    \ MAXLW+1
        |-------------------------------------------------------| \ /
JFNLCK: |          Lock to Prevent Tampering with JFNs          |
        |-------------------------------------------------------|
MAXJFN: |                                                       |
        |-------------------------------------------------------|
ENQLST: |    ENQ Quotas & Counts   |   Pointer to ENQ Q Blocks  |
        |                          |        for this Job        |
        |-------------------------------------------------------|
TIMALC: |               TIMER Clocks Limit                      |
        |-------------------------------------------------------|
LNTABP: |  Pointer to Logical Name Table (Tbl is in JSB Space)  |
        |-------------------------------------------------------|
LNMLCK: |            Lock for Logical Name Data Base            |
                                                    Page 133


        |-------------------------------------------------------|
JOBUNT: |                  Connected Disk Unit                  |
        |-------------------------------------------------------|
JBCLCK: |                    Lock for ASGPAG                    |
        |-------------------------------------------------------| / \
JBCOR:  \    Page Allocation Bit Table for Job Storage Area     \  4
        \                                                       \ \ /
        |-------------------------------------------------------|   --
JSBFRE: |  Ptr. to 1st Free Block  |              0             |    |
        |-------------------------------------------------------|    |
        |                         Lock                          |    |
        |-------------------------------------------------------|
        |                     Space Counter                     |Job area
        |-------------------------------------------------------|  free
        |                Most Common Block Size                 | storage
        |-------------------------------------------------------| header
        |  Max Top of Free Stor.    |  Min. Bottom of Free Stor.|
        |-------------------------------------------------------|    |
        |                         Temp                          |    |
        |-------------------------------------------------------|    |
        |                         Temp                          |    |
        |-------------------------------------------------------|   --
JSFREE: \        Free Storage Area in Job Block (^D64 words)    \ / \
        \                                                       \  |
        \              [Free Blocks have Hdr. Wd of:            \  |
        \               Ptr. to Next Blk,, Length]              \ IJSFRE
        \                                                       \  |
        \                                                       \  |
        |-------------------------------------------------------| \ /
JSSTRT: |                           |  JSSTN                    |*/ \
JSSTRF=0|           Flags           |   Structure Unique Code   |  |
        |-------------------------------------------------------|  |
        |  JSGRP                                                |  |
JSGRPS=1|            AOBJN Pointer to List of Groups            |  |
        |-------------------------------------------------------|  |
        |                           |  JSADN                    | JSSTMX
JSADIR=2|        **Unused**         |Accessed DIR # for This STR| *STRN
        |-------------------------------------------------------|  |
JSFKMT=3|  JSFMT                                                |  |
        |                 Fork-mount bit word                   |  |
        |-------------------------------------------------------|  |
        \                                                       \  |
        \                (4 Words per Structure)                \  |
        \                                                       \  |
        |-------------------------------------------------------| \ /
JSSTLK: |               Lock on the JSSTRT Block                |
        |-------------------------------------------------------|
        |  JSUC                     |  JSDIR                    |
JSBSDN: | Connected STR Unique Code |  Connected Directory #    |
        |-------------------------------------------------------|
        |0           |              |18                       35|
JSBCDS: | JSCDF      |              |JSCDS                      |
        |String Ptr. |              |Ptr. to Connected          |   
        |Valid if set|              |Dir. Name String           |
        |-------------------------------------------------------|
                                                    Page 134


MODES:  |                DDBMOD Word from LOGIN                 |
        |-------------------------------------------------------|
GROUPS: |          Groups to Which LOGIN User Belongs           |
        |-------------------------------------------------------|
RSCNPT: |                    RESCAN Pointer                     |
        |-------------------------------------------------------|
RSCNBP: |     Ptr. to RESCAN Buffer (max. buf. size is 777)     |
        |-------------------------------------------------------|
JBINFO: |          PID of Private <SYSTEM>INFO for JOB          |
        |-------------------------------------------------------|
JSCDR:  |  Next Version # (or -1)   | Adr. of Spool Set String  |
        |                           |       for CDR             |
        |-------------------------------------------------------|
JSMTA1: |  MTA Parity, Density, Mode, and Default Record Size   |*
        |-------------------------------------------------------|
JBFLAG: |       Spooler Flags       |                           |*
        |  (Sent on CLOSE/LOGOUT    |   General Job-wide Flags  |
        |-------------------------------------------------------|
JSLOPD: |          PID to get LOGOUT message from CRJOB         |
        |-------------------------------------------------------|
JSLOJB: |      Job # of Who Logged Out this Job                 |
        |-------------------------------------------------------|
JSFSTK: |      Stack of Things to be Done on Fork Cleanup       |
        |-------------------------------------------------------|
JSFLCK: |            Lock for This JSFSTK Structure             |
        |-------------------------------------------------------|
CRJFLG: |Flag that this is CRJOB Startup.(Used by MEXEC & LOGIN)|
        |-------------------------------------------------------|
        | DCMAX                    | DCCUR                      |
DCNCNT: |  Job's Network Link Quota| Current Count of Open Links|
        |-------------------------------------------------------|
JSSRTM: |      Runtime at Start of this Accounting Session      |
        |-------------------------------------------------------|
JSSCTM: |         Console Time at Start of this Session         |
        |-------------------------------------------------------|
JSATCT: |                 ATS HTN Quota,,Count                  |
        |-------------------------------------------------------|
JOBSKD: |            Special Job Scheduling Parameter           |
        |-------------------------------------------------------|
BATSTF: |           Batch Stream Number and Flags Word          |
        +-------------------------------------------------------+


JFN0:   +-------------------------------------------------------+  --
FILBYT: |            Byte Pointer to Current Window             |   |
        |-------------------------------------------------------|   |
FILBYN: |                Byte # of Current Byte                 |   |
        |-------------------------------------------------------|   |
FILACT: |            Ptr to Account String or Account #         |   |
        |-------------------------------------------------------|   |
FILLEN: |              Total File Length in Bytes               |   |
        |-------------------------------------------------------|   |
FILCNT: |           Bytes Remaining in Current Buffer           |   |
        |-------------------------------------------------------|   |
FILLCK: |                    File Lock Word                     |   |
                                                    Page 135


        |-------------------------------------------------------|   |
FILWND: |      Current Page #       |Location of Current Window |   |
        |-------------------------------------------------------|   |
FILSTS: |     File Status Bits      |       Status       | Mode |*  |
        |-------------------------------------------------------|   |
        |  STR                      |                           |   |
FILDEV: |     Structure Number      |DEV`DTB (i.e.Dev Disp. Tbl)|   |
        |-------------------------------------------------------|   |
FILOFN: |   OFN for This File       | OFN of Long File PT Table |
        |-------------------------------------------------------| JFN
FILLFW: |   Count of Pages Mapped   | Loc. of Page Table Table  | BLOCK
        |-------------------------------------------------------|
FILDDN: |Ptr. to Device String Block|        Directory #        |   |
        |-------------------------------------------------------|   |
        |FILDIR                     | FILATL                    |   |
FILDNM: |   Directory Name String   | Ptr to Attribute List     |   |
        |-------------------------------------------------------|   |
FILNEN: |File Name String Blk. Ptr. |   Ext. String Blk. Ptr.   |   |
        |-------------------------------------------------------|   |
FILVER: | Fork # of JFN Originator  |         Version #         |   |
        |-------------------------------------------------------|   |
        |  FILDMS                   |  FILNMS                   |   |
FILMS1: |    Directory Wild Mask    |      Name Wild Mask       |   |
        |-------------------------------------------------------|   |
        |  FILEMS                   |                           |   |
FILMS2: |    Extension Wild Mask    |                           |   |
        |-------------------------------------------------------|   |
FILFDB: |            Address of FDB in the Directory            |   |
        |-------------------------------------------------------|   |
        |  FILUC                    |  FILPO                    |   |
FILCOD: |      STR Unique Code      |   PTO OFN for Long File   |   |
        |-------------------------------------------------------|  --
        |                 Additional JFN Blocks                 |
        |                           .                           |
        |                           .                           |
        +-------------------------------------------------------+

Each JFN uses a block of 19 (MLJFN) words.  (Since JFNs  can
grow  beyond  the  end of the JSB into successive pages, the
JFN blocks must be the last storage  defined  in  the  JSB.)
MJFN is the maximum number of JFNs.
                                                    Page 136






These definitions are used in the above positions only during the
GTJFN procedure:

(1)  FILTMP / Ptr. to temp string block for default ,, Ptr. to 
               temp string block
(2)  FILPRT / Ptr. to protection string or protection #
(3)  FILSKT / Arpanet connection no.,, Unused
             FILOPT / Byte Ptr. to Store String in GTJFN
        (4)  FILLIB / For DECNET, Ptr to LL Block 
        (5)  FILLNM / Ptr. to RDTEXT buffer ,, Ptr. to logical name
                       chain **
        (6)  FILBFO / For DECNET, Output Buffer Ptr.
        (7)  FILIDX / 0 ,, Index into device tables for original
                       devices GTJFNed
                      {(i.e., doesn't change during spooling)}
             FILBFI / For DECNET, Ptr. to Input Buffer
        (8)  FILBCT / For DECNET, Ptr. to Counts



          **    Logical Name Header Format

        +-------------------------------------------------------+
        |   LNMCNT                  ||   LNMSTP                 |
        |        Depth Count        ||      Step Counter        |
        |-------------------------------------------------------|
        |   LNMLNK                  |    LNMPNT                 |
        |        Link to Next BLK   |  Logical Name String Ptr  |
        +-------------------------------------------------------+

                Bits         Pointer        Content

                 0-17        LNMCNT         Depth count for logical
                                             names
                  18         LMMIDX         Index into logical name
                                             tables
                19-35        LNMSTP         Step counter at time of
                                             chaining

                 0-17        LNMLNK         Link to next chain block
                18-35        LNMPNT         Pointer to logical name
                                             string
                                                    Page 137






FILSTS
  0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 31 35
 +-------------------------------------------------------------------+
 | | | | | | | | | | |  |  |  |  |  |  |  |  |  |  |  |  |  |  |Mode |
 +-------------------------------------------------------------------+        

     FILSTS

       Symbol         Bits     Pointer      Meaning

       OPNF            0                    File is open
       READF           1                    File is OK to read
       WRTF            2                    File is OK to write
       XCTF            3                    File is OK to execute
       RNDF            4                    File is OK to reset ptr.
                                             (i.e., not append)
       NONXF           5                    Non-existent File, delete
                                             FDB on RLJFN
       NWTF            6                    No wait on DUMP I/O
       LONGF           7                    File is a long file
       EOFF            8                    End of file if read
                                             attempted
       ERRF            9                    Bytes read may be wrong
       NAMEF          10                    Name is associated with
                                             this JFN
       ASTF           11                    An * was typed in
       ASGF/BLKF      12                    JFN is being assigned or
                                             service routine wants to
                                             block; shares a bit
                                             position with ASGF
       HLTF           13                    Halt if I/O error
       WNDF           14                    A window page has been
                                              set up
       ENDF/TRNSL     15                    File is past end of maximum
                                             length.
                                            Bit timeshared with ENDF to 
                                             say the JFN is in a trans-
                                             itional state and may not
                                             be accessed.
       SIZE           16                    Illegal to change size of
                                             byte
       FRKF           17                    File is restricted to fork
                                             in LH(FILVER)
       PASLSN         18                    Set to skip line number 
                                             checking on ASCII files
       SKIPBY         19                    Set by BYTINA to remember
                                             that it has to discard.
       XQTAF          20                    Quota exceeded Flag
       FILDUD         21                    Suppress DDMP action if set
       FILINP         22                    Direction of I/O is input
       FILOUP         23                    Direction of I/O is output
                                                    Page 138


       HLDF           24                    Hold in balance set
       RECF           25                    End of record seen
       ACRLFF         26                    Add CRLF's after records on
                                             input
       CRNXT          27                    Return CR next
       LFNXT          28                    Return LF next
       FROSTF         29                    Record has been frosted
                    18-35       IOMODE      Mode File is opened in

SYSFK.HLP

Work 0 of 4-word structure block (starts at JSSTRT)

       0 1 2 3                     17 18                         35
      +------------------------------------------------------------+
      | | | |                        |  JSSTN                      |
      | | | |                        |       Structure Unique Code |
      +------------------------------------------------------------+

Symbol  Bit       Pointer       Content

         0        JSSDM         Structure is dismounted
         1        JSMCI         Mount count has been incremented by
                                 structure
         2        JSXCL         Structure is mounted exclusively by 
                                 the structure
JSFRST 18-35     JSSTN         Structure unique code



       0            9 10 11  14 15  17 18                        35
      +-------------------------------------------------------------+
      |              |  | JSMTD |JSMTM |  JSMTR                     |
JSMTA1|              |  |Density| Mode |        Default Record Size |
      +-------------------------------------------------------------+

        Bits     Pointer        Content

         10      JSMTP          Default Parity
        11-14    JSMTD          Default Density
        15-17    JSMTM          Default Mode for transfers
        18-35    JSMTR          Default record size (hardware bytes)



      0 1 2 3 4                                                  35
      +------------------------------------------------------------+
JBFLAG| | | |                                                      |
      +------------------------------------------------------------+

        Symbol       Bits       Pointer      Content

        SP%BAT        0         JSBAT        Job is being controlled
                                              by BATCH
        SP%DFS        1         JSDFS        Spooling is deferred
                                                    Page 139


        SP%ELO        2         JSELO        Job executed LOGOUT JSYS
        SP%FLO        3         JSFLO        Job forced to LOGOUT by 
                                              top Fork error
        SP%OLO        4         JSOLO        Job logged out by other
                                              job
                     18         JBMX         Job has been in the
                                              mini-exec
                     19         JBT20        Job is at TOPS-20 command
                                              level
                                                    Page 140


                            KDB

Kontroller Data Block (TM02/3, DX20 only)

Defined in:  PHYPAR

Referenced by:  PHYM2

                                Format

        +-------------------------------------------------------+
KDBSTS=0|           Flags           |         Unit Type         |
        |-------------------------------------------------------|
KDBIUN=1|            Initial AOBJN Word to UDB Table            |
        |-------------------------------------------------------|
KDBCUN=2|            Current AOBJN Word to UDB Table            |
        |-------------------------------------------------------|
KDBDSP=3|             Dispatch for Service Routine              |
        |-------------------------------------------------------|
KDBDDP=4|                                                       |
=KDBUDB \                  UDB Pointer Table                    \
        |                                                       |
        |                                                       |
        |                                                       |
        |                                                       |
        |                                                       |
        |-------------------------------------------------------|
        \                 Device Dependent Code                 \
        |                                                       |
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+


Device dependent sector for TM02/3

        +-------------------------------------------------------+  ^
KDBUDB= |                   UDB Pointer Table                   |  |
KDBPP   |                                                       | D8
        |                                                       |  |
        |                                                       |  v
        |-------------------------------------------------------|
TM2ADR= |              Massbus Address of TM02/3                |
        |-------------------------------------------------------|
SAVUDB= |               Current UDB (0 if none)                 |
        |-------------------------------------------------------|
TM.CNI= |                 CONI of RH 8ocshere                   |
        |-------------------------------------------------------|
TM.CSI= |               DATAI RH control Register               |
        |-------------------------------------------------------|
TM.DBF= |                DATAI RH Data Register                 |
        |-------------------------------------------------------|
TM2REG= |               Drive Registers go here                 |
        +-------------------------------------------------------+
                                                    Page 141





         0 1                  17 18                        35
        +----------------------------------------------------+
KDBSTS  | | |                   |                            |
        +----------------------------------------------------+


              Symbol       Bit      Pointer      Content

              KS.ACT        1                    Controller Active if set
              KS.HLT        2                    Microcode is halted
                          18%-35                  Unit type


Device dependent sector for DX20


        +------------------------------------------------------+  ^
K.DUDB= |                   UDB Pointer Table                  |  |
KDBDDP  |                                                      |  |
        |                                                      | NUMDRV
        |                                                      |  |
        |                                                      |  |
        |------------------------------------------------------|  v
K.DNUM= |         Number of Drives in UDB Pointer Table        |
        |------------------------------------------------------|
K.DXAD= |                Massbus Address of DX20               |
        |------------------------------------------------------|
K.SUDB= |                Current UDB (0 if none)               |
        |------------------------------------------------------|
K.DCNI= |                 CONI of RH goes here                 |
        |------------------------------------------------------|
K.DCS1= |               DATAI RH Control Register              |
        |------------------------------------------------------|
K.DDBF= |                DATAI RH Data Register                |
        |------------------------------------------------------|
K.DUER= |                  Microcode Version                   |
        |------------------------------------------------------|
K.DRRG= |               Drive Registers go here                |  ^
        |                                                      |  |
        |                                                      |  |
        |                                                      | D22
        |                                                      |  |
        |                                                      |  |
        |------------------------------------------------------|  v
K.DEST= |                Extended Status Table                 |  ^
        |                                                      |  |
        |                                                      |  |
        |                                                      | D20
        |                                                      |  |
        |                                                      |  |
        +------------------------------------------------------+  v
                                                    Page 142


                     LOGICAL LINK BLOCK

The logical  link  block  is  the  data  structure  used  in
management NSP logical links.  There is a logical link block
for each logical link known to TOPS-20.

Defined in:  NSPSRV

Referenced in:  NSPSRV


                                 Format

        +-------------------------------------------------------+
 LLUPL  |                      Up Pointer                       |
        |-------------------------------------------------------|
 LLDWN  |                     Down Pointer                      |
        |-------------------------------------------------------|
        || LLSTA | LLFLG            | LLLNK                     | *
        ||       |    Link Flags    |      This Link's ID       |
        |-------------------------------------------------------|
        | LLFRK                     | LLDRC  | LLPII  | LLPIC   |
        |        Owning Fork        |Data PI | Int PI | CI PI   |
        |-------------------------------------------------------|
        | LLIIN           | LLFNM     | LLHLK                   |
        |  Segment # for  |  Remote   |       Link ID on        |
        | Incoming LS/INT | Object #  |      Foreign Host       |
        |-------------------------------------------------------|
 LLMSG  |               Ptr. to Raw Message Queue               |
        |-------------------------------------------------------|
 LLMSI  |               Ptr. to Interrupt Message               |
        |-------------------------------------------------------|
        |||  | LLSWG                 | LLMSM     | LLQUN | LLQOU| *
        |||  |   Max. Segment Size   |           |       |      |
        |-------------------------------------------------------|
        ||  |||  | LLOPT                                        | *
        ||  |||  |                                              |
        |-------------------------------------------------------|
        | Next Data Xmit  | Next LS/INT Xmit |Next Data Receive |
        |    Segment #    |    Segment #     |    Segment #     |
        |-------------------------------------------------------|
 LLOMSG |             Ptr. to Ordered Message Queue             |
        |-------------------------------------------------------|
        | LLUCT  | LLTSK                                        |
        |        |              Ptr. to Task Name               |
        |-------------------------------------------------------|
 LLHST  |               Ptr. to Remote Host Name                |
        |-------------------------------------------------------|
        | LLMIC  | LLFDS                                        |
        |        |                                              |
        |-------------------------------------------------------|
 LLBPTR |                 Working Byte Pointer                  |
        |-------------------------------------------------------|
 LLBPCT |                  Current Byte Count                   |
        |-------------------------------------------------------|
                                                    Page 143


        | LLBSZ  |LLDRW|LLDMT ||LLLSC| LLRSN                    |
        |        |     |      ||     |  Disconnect Reason Code  |
        |-------------------------------------------------------|
 LLSEGQ |                 Header for Sent Queue                 |
        |-------------------------------------------------------|
        | LLNAM                     | LLSOB                     |
        |    No. of This Object     |    Object of Remote CI    |
        |-------------------------------------------------------|
 LLDSC  |               Ptr. to Descriptor Block                |
        |-------------------------------------------------------|
 LLUSR  |                Ptr. to User Name Block                |
        |-------------------------------------------------------|
 LLACT  |            Ptr. to Accounting String Block            |
        |-------------------------------------------------------|
        | LLPCT  | LLPSW                                        |
        |        |            Ptr. to Password Block            |
        |-------------------------------------------------------|
 LLUSGP |                  User, Group from CI                  |
        +-------------------------------------------------------+
                                                    Page 144


                  LOGICAL-NAME-DEFINITION

Logical Name Definition Block.  The block format given below
is  used  for  system and job-wide logical name definitions.
The first definition block for a logical name is pointed  to
by  its Logical Name List and is store in the swappable free
space if a system logical name or in  the  JSB  space  if  a
job-wide logical name.

Defined in:  LOGNAM

Reference by:   LOGNAM


          +-------------------------------------------------------+
  LNBLK=0 |   PTR TO NEXT DEFINITION  |    SIZE OF THIS BLOCK     |
          |     (OR ZERO IF NONE)     |       (USUALLY 12)        |
          |-------------------------------------------------------|
  LNDEV=1 |        ASCII BYTE PTR TO DEVICE BLOCK (IF ANY)        |
          |-------------------------------------------------------|
  LNDIR=2 |      ASCII BYTE PTR TO DIRECTORY BLOCK (IF ANY)       |
          |               (-3 MEANS STAR WAS TYPED)               |
          |-------------------------------------------------------|
  LNNAM=3 |       ASCII BYTE POINTER TO NAME BLOCK (IF ANY)       |
          |-------------------------------------------------------|
  LNEXT=4 |       ASCII BYTE POINTER TO FILE TYPE (IF ANY)        |
          |         (-2 MEANS A NULL FIELD WAS SPECIFIED)         |
          |-------------------------------------------------------|
  LNVER=5 |        500000,,0 + GENERATION NUMBER (IF ANY)         |
          |-------------------------------------------------------|
  LNACT=6 |           500000,,0 + ACCOUNT NUMBER  -OR-            |
          |     ASCII BYTE POINTER TO ACCOUNT STRING (IF ANY)     |
          |-------------------------------------------------------|
  LNPRT=7 |         500000,,0 + FILE PROTECTION (IF ANY)          |
          |-------------------------------------------------------|
  LNTMP=10|      0 IF PERMANENT OR -1 IF TEMPORARY (IF ANY)       |
          |-------------------------------------------------------|
  LNATR=11| PREFIX VALUE OF CURRENT   |   PTR TO ATTRIBUTE CHAIN  |
          |          PREFIX           |                           |
          +-------------------------------------------------------+
                                                    Page 145


                     LOGICAL-NAMES-LIST

Logical Names List.  The list described below is the  format
used  for  the  system  logical  names  list  (pointed to by
SYLNTB) and the job wide logical names list (pointed  to  by
the JSB entry, LNTABP.)

The system logical names list is built in the swappable free
space  from  the  entries in SYNMTB at system initialization
time.  (See SWAP-FREE-SPACE and  SYNMTB  tables).   A  job's
logical  names list is built in the JSB space the first time
a logical name is created.

An entry in a logical  names  list  has  a  pointer  to  the
logical  name  string (in ASCIZ) in the left half and a link
to the  first  definition  block  in  the  right  half  (See
LOGICAL-NAME-DEFINITION description).

Defined in:  STG

Referenced by:  LOGNAM


        +-------------------------------------------------------+
        |  # OF DEFINED LOG NAMES   | SPACE ALLOCATED IN TABLE  |
        |-------------------------------------------------------|
        |   LOGICAL NAME BLK ADDR   | LINK TO FIRST DEFINITION  |
        |-------------------------------------------------------|
        |   LOGICAL NAME BLK ADDR   | LINK TO FIRST DEFINITION  |
        |-------------------------------------------------------|
        \                           .                           \
        \                           .                           \
        +-------------------------------------------------------+
                                                    Page 146


                      LPT-STORAGE-AREA

Line Printer Storage Area.  Each entry in the resident  area
is  LPTN  words  long,  where LPTN equals the number of line
printers on the system.

Defined in:  STG

Referenced by:  LINEPR


                                Format

        +-------------------------------------------------------+  ^
LPTTYP: \        Type of LPT Vector for Dev. Independence       \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \* ^
LPTSTS: \                      Status Word                      \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \* ^
LPTST1: \                  Second Status Word                   \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTST2: \                   Third Status Word                   \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTST3: \                  Fourth Status Word                   \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \* ^
LPTERR: \                    Last Error Word                    \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTCNT: \                    Buffer Counter                     \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTCLS: \                  LPTCHK Clock Switch                  \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTCCW: \                    BLKI/O Pointer                     \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTICT: \                 Interrupt Byte Count                  \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTCKT: \                  Interval for LPTTIM                  \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
LPTLCK: \                 Lock on Opening LPT                   \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
PGDATA: \            Page Counter to be Sent to -11             \ LPTN
        +-------------------------------------------------------+  v
                                                    Page 147


        The following LPT: storage items are in the nonresident area 
        of the monitor.



        +-------------------------------------------------------+  ^
LPTBUF: \     2 Buffers (each NLPBF=400 words) for Each LPT:    \ LPTN*2*NLPBF
        |-------------------------------------------------------|  v
        \  VFUOFN                   |  RAMOFN                   \  ^
LPTOFN: \            VFU            |            RAM            \  |
        \    OFN's to Prevent Opens for Write (1 entry/DTE)     \ LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
VFUFIL: \       Swappable Storaeg Area for VFU File Names       \ LPFLSZ*LPTN
        |-------------------------------------------------------|  v
        \                                                       \  ^
RAMFIL: \       Swappable Storage Area for RAM File Names       \ LPFLSZ*LPTN
        +-------------------------------------------------------+  v




       If the assembly flag, SMFLG, is set, indicating a 2020 Monitor,
       then the following additional storage is assembled in the 
       resident area of the monitor.


        +------------------------------------------------------+
L11A:   |            Holds Fake -11 Adr of Buf                 |
        |                  (1 entry / LPT )                    |
        |------------------------------------------------------|
LPWINA: |              Address of Unibus Window                |
        |------------------------------------------------------|  ^
LPACS:  |            AC Storage During LPT Interrupt           |  |
        |                                                      |  6
        |------------------------------------------------------|  v
LPSTAK: |                                                      |  ^
        |                 PDL During LPT Interrupt             | LPSLEN
        |                                                      |  |
        |------------------------------------------------------|  v
LPXJEN: |         XJEN Instr. for Dismissing LPT Interrupt     |
        |------------------------------------------------------|  ^
LPXPTB: |    LPT Interrupt Instr. is XPCW to this 4-word Blk   | LPTN(1)*4
        +------------------------------------------------------+  v
                                                    Page 148





        0               11 12              23 24                   35
       +-------------------------------------------------------------+
       |  LPTFE           |  LPTMX           | | | | | | | | | | | | |
LPTSTS:|Bytes Now in Front|Max. Bytes Allowed| | | | | | | | | | | | |
       | End              | in FE            | | | | | | | | | | | | |
       +-------------------------------------------------------------+

            Symbol     Bits    Pointer   Content

            LP%%FE     0%-11    LPTFE     Bytes now in front end
            LP%%MX    12%-23    LPTMX     Max. bytes allowed in front end
            LP%%LHC      24     LPLHC     Loading has completed flag for 
                                         RAM/VFU load
            LP%%HE       25     LPTHE     Hard error on this LPT:
            LP%%OBF      26     LPOBF     Output is being flushed
            LP%%MWS      27     LPMWS     MTOPR is waiting for a status to
                                          arrive
            LP%%ER       28     LPTER     LPT had an error
            LP%%OL       29     LPTOL     LPT on%-line
            LP%%TBL      30     LPTBL     LPT is over allocation
            LP%%TWT      31     LPTWT     Request on Q.
            LP%%THN      32     LPTHN     DTEQ failed
            LP%%OPN      33     LPOPN     LPT is opened
            LP%%ALI      34     ALTI      Interrupt buffer pointer
            LP%%ALP      35     ALTP      Buffer Pointer
                                                    Page 149




        0         5 6              17 18 19 20                   35
       +-----------------------------------------------------------+
       | LPPSI     |LPPAG            |  |  | LPSST                 |
LPTST1:|PSI Chan. #|   Page Counter  |  |  |   Software Status Word|
       +-----------------------------------------------------------+

           Symbol    Bits     Pointer   Content

           LP%%SSI   0%-5      LPPSI     Channel # on which PSI's are
                                         desired
           LP%%PAG   6%-17     LPPAG     Page Counter
           LP%%LCP     18      LPLCP     Lower case printer
           LP%%SHA     19      LPSHA     Status has arrived
           LP%%SST  20%-35     LPSST     Software status word
        
                                         Symbol   Bits   Content
        
                                         .DVFFE    28    Device has a
                                                         fatal, unre%-
                                                         coverable error
                                         .DVFLG    29    Error logging 
                                                         information
                                                         follows
                                         .DVFEF    30    EOF
                                         .DVFIP    31    I/O in progress
                                         .DVFSE    32    Software condition
                                         .DVFHE    33    Hardware error
                                         .DVFOL    34    Offline
                                         .DVFNX    35    Nonexistent device
                                                    Page 150


         0  1              12  13                 28  29  30        35
        +-------------------------------------------------------------+
LPTST2: |  |   SAVBCT        |  SAVBUS               |   |            |
        +-------------------------------------------------------------+

             Bits      Pointer      Content

              0        ARROWF       Convert control to arrow character
             1-12      SAVBCT       Saved byte counter during arrow
            13-28      SAVBUS       Saved bus address register
              29       LPTLOR       On when loading ram

- - - - - - -
only for 2020

         0  1             8 9                  23 24                35
        +-------------------------------------------------------------+
LPTST3: |  |  SAVCHR       |  LPTCC              |                    |
        +-------------------------------------------------------------+

             Bits      Pointer     Content

              0        LPXBIT      On if printer exists
             1-8       SAVCHR      Saved LP buffer character
            24-35      LPTCC       Count of characters sent to printer
                                                    Page 151



        0                      17 18 19 20                         35
       +-------------------------------------------------------------+
       |  LPFRK                  |  |  |  LPERR                      |
LPTERR:|   Fork ID of Owning PSI |  |  |     Last Error Indication   |
       |    Program              |  |  |                                  |
       +-------------------------------------------------------------+


            Symbol     Bits          Pointer      Content

            LP%FRK     0-17          LPFRK        Fork ID of owning PSI
                                                  process
            LP%MSG      18           LPMSG        If on, suppress standard
                                                  messages
            LP%PCI      19           LPPCI        Page counter has
                                                  interrupted
            LP%ERR    20-35          LPERR        Last error indication




        0        5                  16 17 18                      35
       +------------------------------------------------------------+
       |  LPBSZ   |              |  |  |                         |
LPTCLS:| Byte Size|                 |  |  |                         |
       +------------------------------------------------------------+

            Symbol     Bits         Pointer       Content

            LP%BSZ     0-5          LPBSZ         Byte size of OPENF
            LP%RLD      16          LPRLD         Front end was reloaded
            LP%NOE      17          LPNOE         Note occurrence of EOF
                                                    Page 152





        0                   15 16 17                 31 32 33 34 35
       +-----------------------------------------------------------+
       |  PGFNC               |  | PGCTR               |  |  |  |  |
PGDATA:|Function Code:  Load  |  |   Page Counter Value|  |  |  |  |
       | Page Ctr.            |  |                     |  |  |  |  |
       +-----------------------------------------------------------+

            Symbol    Bits           Pointer      Content

                      0%-15           PGFNC        Function code:  load 
                                                   page counter
                       16            PGENB        Enable interrupts
                     17%-31           PGCTR        Page counter value
            LP%%IRP     32            LPIRP        Interrupt request
                                                   pending
            LP%%RBR     33            LPRBR        RAM or VFU being
                                                   reloaded
            LP%%LTR     34            LPLTR        Translation RAM
                                                   requires reloading
            LP%%LVF     35            LPLVF        VFU requires reloading
                                                    Page 153


                     MONITOR-STATISTICS

This table is available through GTTAB and is used by  WATCH,
EXEC, etc.

Defined in:  STG

Referenced by:  MEXEC, PAGEM, SCHED, TTYSRV

                                  Format

        +-------------------------------------------------------+
SKDTM0: |      Time spent in SKDNUL with balance set empty      |
        +-------------------------------------------------------+
SKDTM1: |    Time spent in SKDNUL with balance set non-empty    |
        +-------------------------------------------------------+
SKDTM2: |             Time spent running scheduler              |
        +-------------------------------------------------------+
SPTTIM: |             Time spend in pager trap code             |
        +-------------------------------------------------------+
DRMRD:  |                 Number of drum reads                  |
        +-------------------------------------------------------+
DRMWR:  |                 Number of drum writes                 |
        +-------------------------------------------------------+
DSKRD:  |                 Number of disk reads                  |
        +-------------------------------------------------------+
DSKWR:  |                 Number of disk writes                 |
        +-------------------------------------------------------+
TTYBKS: |                 Number of tty wakeups                 |
        +-------------------------------------------------------+
TTINTS: |             Number of terminal interrupts             |
        +-------------------------------------------------------+
BSTSUM: |                 Integral of NBPROC DT                 |
        +-------------------------------------------------------+
RJTSUM: |             Integral of NBPROC+NGOJOB DT              |
        +-------------------------------------------------------+
RJAV:   |     Exponential average of number runnable forks      | / \
        |                                                       | NRJAVS
        |                                                       |  =3
        \                                                       \ \ /
        +-------------------------------------------------------+
DSKWT:  |            Sum of process disk wait times             |
        +-------------------------------------------------------+
DRMWT:  |            Sum of process drum wait times             |
        +-------------------------------------------------------+
NTTYIN: |        Total number terminal input characters         |
        +-------------------------------------------------------+
NTTYOT: |        Total number terminal output characters        |
        +-------------------------------------------------------+
NGCCOR: |                    Count of GCCORs                    |
        +-------------------------------------------------------+
GCCTIM: |                Integral of GCCOR time                 |
        +-------------------------------------------------------+
NREMR:  |          Count of WS removals while runnable          |
        +-------------------------------------------------------+
                                                    Page 154


BSWT:   |               Sum of process wait times               |
        +-------------------------------------------------------+
SKDOVH: |      Accumulated SCHED overhead time in HP units      |
        +-------------------------------------------------------+
SKDIDL: |           Accumulated idle time in HP units           |
        +-------------------------------------------------------+
SKDSWP: |        Accumulated swap-wait time in HP units         |
        +-------------------------------------------------------+
USRTIM: |         Accumulated user time in milliseconds         |
        +-------------------------------------------------------+
HQFSUM: |                 Integral of NGQFK DT                  |
        +-------------------------------------------------------+
LQFSUM: |                 Integral of NLQFK DT                  |
        +-------------------------------------------------------+
DWRWT:  |            Sum of process disk write wait             |
        +-------------------------------------------------------+
NAJBAL: |             Number of forced AJBALS calls             |
        +-------------------------------------------------------+
SNRSUM: |                  Integral of SUMNRN                   |
        +-------------------------------------------------------+
RPQSUM: |                   Integral of NRPLQ                   |
        +-------------------------------------------------------+
HSPTIM: |                  HP pager trap time                   |
        +-------------------------------------------------------+
NCSWCH: |              Number of context switches               |
        +-------------------------------------------------------+
BGNDTM: |       Time doing background stuff (TTCH7, etc.)       |
        +-------------------------------------------------------+
STRPCT: |                System total page traps                |
        +-------------------------------------------------------+
SRPQSC: |            System total "saves" from RPLQ             |
        +-------------------------------------------------------+
SGCCWR: |               Number writes from GCCOR                |
        +-------------------------------------------------------+
NWSSUM: |            Integral of number WS in memory            |
        +-------------------------------------------------------+
SKDFIL: |       Integral of wait time with out swap waits       |
        +-------------------------------------------------------+
NWSLOD: |                   Count of WS loads                   |
        +-------------------------------------------------------+
NREMJ:  |     Count of balance set removals while runnable      |
        +-------------------------------------------------------+
SXGCWR: |                Number writes from XGC                 |
        +-------------------------------------------------------+
                                                    Page 155


                      MTA-STORAGE-AREA

Magtape storage area;  each entry (unless  otherwise  noted)
is  MTAN  words long where MTAN equals the number of magtape
units on the system.

Defined in:  STG

Referenced by:  MAGTAP


                                Format


        +-------------------------------------------------------+  ^
MTALCK: \                       Lock Word                       \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \* ^
MTASTS: \                    Status of Unit                     \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \* ^
MTARS1: \             Resident Storage for Magtape              \ MTAN
        |-------------------------------------------------------|  v
MTINDX: |             Number of Real MTAs on System             |
        |-------------------------------------------------------|  ^
MTPSFK: |           Fork 4          |           PST             | MTAN
        |-------------------------------------------------------|  v
MTCUTB: \         CDB Table         |         UDB Table         \  ^
        \                           |       (1 Entry/UDB)       \  |
        \                           |                           \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTAPBF: \            Space for Buffer Page Pointers             \ MTPBFL=
        \                                                       \ MTB4FN*MAXPPB+
        \                                                       \ MTPN
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTIRBF: \                    Space for IORBs                    \ MTABFL=
        \                                                       \ MTAN*MTBUFN*
        \                                                       \ MTIRBL
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTIOWD: \                IOWD for Next Transfer                 \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTBIOW:  \           Backup IOWD for Next Transfer              \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTAOLS: \  Length of last Xfer      |                           \ MTAN
        |-------------------------------------------------------|  v
        \                                                       \  ^
MTARCE: \                   Total Error Count                   \ MTAN
        |-------------------------------------------------------|  v
REWCNT: |               Number of Rewinding Units               | 
        |-------------------------------------------------------|  
                                                    Page 156


MTERAS: |                 Rewrite Erase Counter                 |
        |-------------------------------------------------------|
MTPNTR: |                 IOWD During Transfer                  |
        |-------------------------------------------------------|
MTAUNT: |         Unit Currently Attached to Controller         |
        |-------------------------------------------------------|
MTERRC: |                     Retry Counter                     |
        |-------------------------------------------------------|
MTERFL: |                    State of Retry                     |
        |-------------------------------------------------------|
MTACOM: |            CONO Word of Current Operation             |
        |-------------------------------------------------------|
MTDINR: |           Return Address for Data Interrupt           |
        |-------------------------------------------------------|
MTACLS: |      Clock Routine Switch, 0 for No Clock Wanted      |
        |-------------------------------------------------------|  ^
TLABBP: |               PNTR to Locked Buffer Page              | 2XMTAN
        |-------------------------------------------------------|  v
TLABRO: |                            |  RCNT                    |  ^
        |        Resitent flags      |    Record count info     | MTAN
        +-------------------------------------------------------+  v


        The following MTA storage items are in the nonresident area
        of the monitor and each item is MTAN words long.


         0                        17 18                       35
        +-------------------------------------------------------+* ^
        |                           |  MTRS                     | MTAN
MTANR1: \   Flags, Density, Mode    |  Rec size in Hdw. Bytes   \  v
        |-------------------------------------------------------|  ^
        |  MTBYT                    |  MTBUF                    | MTAN
MTANR2: \   Initial LH of FILBYT    | Ptr. to Buffer Pages List \  v
        |-------------------------------------------------------|  ^
        | 0     5|6     11|12     17|18    23|                  |  |
        | MTHBW  | MTUBW  | MTCSB   | MTCUB  |                  |  |
MTANR3: \Hdw.Byts|UserByts|Current  | Current|                  \ MTAN
        | Per Wd | Per Wd |Service  | User   |                  |  |
        |        |        |Routine  | Buffer |                  |  |
        |        |        |Buffer   |        |                  |  v
        |-------------------------------------------------------|  ^
        |  MTCIRB                   |  MTCUP                    |  |
MTANR4: \    Current IORB in Use    |     Current User Page     \ MTAN
        |-------------------------------------------------------|  v
        |  MTUBB                    |  MTUBP                    |  ^
MTANR5: \   User Bytes per Buffer   |    User Bytes per Page    \ MTAN
        |-------------------------------------------------------|  v
        |  MTALTC                   |  MTLIRB                   |  ^
MTANR6: \    Last Transfer Count    | Last Dump Mode IORB Adr.  \ MTAN
        |-------------------------------------------------------|  v
        |                                                       |* ^
TLABL0: |                         Flags                         | MTAN
        |-------------------------------------------------------|  v
        |  TPERM                    |  TPFRK                    |  ^
                                                    Page 157


TLABL1: |   Error codeset by MTCON  |     Tape fork for PSI     | MTAN
        |-------------------------------------------------------|  v
        |  TPJFN                    |  TPLBLS                   |  ^
TLABL2: |         Saved JFN         | Tape label buffers in SWAP| MTAN
        |-------------------------------------------------------|  v
        |  FSSAV                                                |  ^
TLABL3: |               Place to save file status               | MTAN
        |-------------------------------------------------------|  v
        |     flags, section #      |  TPMTRS                   |* ^
TLABL4: |                           |    Place to save Rec Size | MTAN
        |-------------------------------------------------------|
        |                                                       |* ^
TLABL5: |                  Tape position info                   | MTAN
        |-------------------------------------------------------|  v
        |  TPBSZ                    |  TPRSZ                    |  ^
TLABL6: |       File blocksize      |     File record size      | MTAN
        |-------------------------------------------------------|  v
        |  TPSOUP                   |  TPIOB                    |  ^
TLABL7: |  Saves Cur. pg. PTR for   |    I/O buffer address     | MTAN
        |   TPSBYT                  |                           |  v
        |-------------------------------------------------------|  ^
        |  SVIOS                                                |  |
TLABL8: |                   Place to save IOS                   | MTAN
        |-------------------------------------------------------|  v
        |  SVBLK                                                |  ^
TLABL9: |              Place to save black address              | MTAN
        |-------------------------------------------------------|  v
        |  TPLRC                    |  TPPRO                    |* ^
TLABL10:|       Local Status        |        Protection         | MTAN
        |-------------------------------------------------------|  v
        |  TPOCT                    |  TPOBY                    |
TLABL11:|       old TPFCNT          |        old TPFBYN         |
        |-------------------------------------------------------|
        |  TPFSN                                                |
TLABL12:|                Sixbit volume set name                 |
        |-------------------------------------------------------|
        |  TPEXPD                                               |
TLABL13:|                   Expiration date                     |
        |-------------------------------------------------------|
TPFCNT: |                      MT filcnt                        |
        |-------------------------------------------------------|
TPFBYN: |                      MT filbyn                        |
        |-------------------------------------------------------|
TPFLEN: |                      MT fillen                        |
        |-------------------------------------------------------|
TPFLNX: |        Count of Bytes Expected in next Record         |
        |-------------------------------------------------------|
TPSBYT: | Pointer to where JCW should go when record is complete|
        |-------------------------------------------------------|
MTAJB0: |         JOB 0 flag for MTA unit came on line          |
        +-------------------------------------------------------+
                                                    Page 158





        0 1 2 3 4 5 6 7 8 9         17 8 9 0 1 2 3 4 5 6 7 8 9  1 2  35
       +---------------------------------------------------------------+
MTASTS | | | | | | | | | |            | | | | | | | | | |   |    |     |
entry  +---------------------------------------------------------------+



           Symbol       Bits         Content

           OPN           0           Unit has been opened
           OPND          2           Unit has been opened for
                                      dum mode
           DMPWT         3           Waiting for a dump mode
                                      operation to finish
           LTERR         4           Error Occurred on last
                                      dump mode operation
           BUFA          5           Buffers have been assigned
           CLOF          6           CLOSF in progress
           MTOWT         7           MTOPR in progress
           MTIELW        8           Inhibit error logging
           MTNOWT        9           Don't set MTOWT
           MT%ILW       18           Write lock
           MT%DVE       19           Hardware device error
           MT%DAE       20           Data error
           MT%%SER       21           No error retry
           MT%EOF       22           EOF
           MT%IRL       23           Illegal record length
           MT%BOT       24           Beginning of tape
           MT%EOT       25           Physical end of tape
           MT%EVP       26           Even Parity
           MT%DEN      27-28         Density (0 is normal)
                                        .MTLOD=1 Low Density
                                         (200 BPI)
                                        .MTMED=2 Medium Density
                                         (556 BPI)
                                        .MTHID=3 High Density
                                         (800 BPI)
           MT%CCT      29-31         Character Counter
           MT%NSH       32           Mode or density not supported
                                      by hardware
                                                    Page 159








         0                                    19 20 21   29 30    35
        +-----------------------------------------------------------+
 MTARS1 |                                        | | MTPPB |MTNIR/  |
 entry  |                                        | |# of   |  MTANIR|
        |                                        | |Pgs/Buf|        |
        +-----------------------------------------------------------+

           Bits       Pointer      Content

            20        ABORTF       An error occurred and IORBs aborted
          21-29       MTPPB        Number of pages per buffer
          30-35       MTNIR        Number of IORBs queued
          30-35       MTANIR       Absolute version of MTNIR


         0  1  2      8 9  10 11 12  14 15  17 18                 35
        +-----------------------------------------------------------+
 TLABR0 |  |  |        |  |  |  |      |      |                     |
 entry  +-----------------------------------------------------------+


           Bits        Pointer     Content

            0          TPVV        Volume valid flag
            1          TPNVV       Tape not valid
           2-8         TPUNIT      Actual mta unit
            9          SNEOT       EOT seen while writing labels
           11          TPEDB       EBCDIC Volume
          12-14        TPMTDM      Place to save data mode
          15-17        TPMHEW      Place to save bytes/wd
          18-35        RCNT        Record count info
                                                    Page 160





         0 1 2    5 6 7 8  10 11  14 15  17 18                     35
        +------------------------------------------------------------+
 MTANR1 |   |MTFCN | | |MTSTC| MTDN |MTDM |MTRS                      |
        |   |      | | |     |      |     | Record Size in Hdw. Bytes|
        +------------------------------------------------------------+

           Bits       Pointer     Content

           0-1        MTNTM       Count of EOFs written
           2-5        MTFCN       Last function performed
            6         MTPAR       Parity
            7         MTRBF       Reading backwards flag
           8-10       MTSTC       CLOSF function counter
          11-14       MTDN        Density
          15-17       MTDM        Data mode
          18-35       MTRS        Record size in hardware bytes



        0    5 6  12 13 14 15 16 17 18 19 20 21 22 23 24 25  27 28 31 32  35
       +--------------------------------------------------------------------+
TLABL0 |      |     |  |  |  |  |  |  |  |  |  |  |  |  |      |     |N Used|
entry  +--------------------------------------------------------------------+


           Bits       Pointer     Content

           0-5        TPSTAT      State code
           6-12       TPLPCS      Label processing code
            13        TPBEGF      Set if beginning of spanned record
            14        TPNBL       New block read
            15        TPUED       Use EBCDIC data if set
            16        TPFVM       If set, first volume is mounted
            17        TPLCT       User label count
            18        HDR1        HDR1 data valid
            19        HDR2        HDR2 data valid
            20        RCCHK       Record count check error (TLRCHK)
            21        TPEOF       EOF 1/2 inch in TLRCHK (also EOV)
            22        TPT20       TOPS-20 volume
            23        UVLD        UVLD data valid
            24        TPLBD       Unlabeled/labeled operation
          25-27       TPDNS       MTA density - declared by MTCON
          28-31       TPNUL       # of user labels written
                                                    Page 161




        +--------------------------------------------------------------+
 TLABL4 |  |  |  |  TPPSI   |  TPFSEC   |  TPMTRS                      |
 entry  +--------------------------------------------------------------+


           Bits       Pointer     Content

            0         TPEUT       End of user labels encountered
            1         TPAPP       Open for append
            2         TPDPN       MT opened
           3-8        TPPSI       Tape PSI for EOV
           9-17       TPFSEC      File section number
          18-35       TPMTRS      Place to save record size



         0    4  5 6     11 12 13 14     17 18         26 27         35
        +--------------------------------------------------------------+
 TLABL5 |      |  |        |     |         |             |             |
 entry  +--------------------------------------------------------------+


           Bits       Pointer     Content

            5         TPDVS       Defer volume switch if set
           6-11       TPFRMT      Record format type code
          12-13       TPMOD       Tape mode
          14-17       TPRVN       Relative volume number
          18-26       FSEQ        Tape file position (seq. #)
          27-35       USRSEQ      User requested seq. #




         0  1 2                         17 18                        35
        +--------------------------------------------------------------+
 TLABL10|    |  TPLRC                     |  TPPRO                     |
 entry  +--------------------------------------------------------------+


           Bits       Pointer     Content

           0-1        TPXLB       Extra label count
           2-17       TPLRC       Count of last read record
           0-17       TPGDS       Local status
          18-35       TPPRO       Save protection here
                                                    Page 162


                           MTCUTB

This table contains the address of the CDB and the  UDB  for
each  tape  drive on the system or the entry contains a zero
if the drive does not exist.

Defined in:  STG

Referenced by:  DEVICE, MAGTAP, PHYM2, PHYSIO, PHYX2, TAPE

Index:  Tape drive number

                                 Format

        +-------------------------------------------------------+
MTCUTB: |            CDB            |            UDB            | / \
        +-------------------------------------------------------+  |
        |                           .                           |  |
        |                           .                           | MTAN
        |                           .                           |  |
        \                           .                           \  |
        |                           .                           | \ /
        +-------------------------------------------------------+
                                                    Page 163


                           NAMUTP

Name Unit Type Pointers.  This table  contains  pointers  to
unit  type  names  for  disks  (i.e.,  RP06, RM03, etc.) and
magtapes (i.e., TU45, TU77, etc.).

Defined in:  PHYSIO

Referenced by:  PHYSIO


                                Format

        +-------------------------------------------------------+
NAMUTP: |         POINT 7,[ASCIZ/ (Illegal Type: 0) /]          |
        |-------------------------------------------------------|
        |                 POINT 7,[ASCIZ/RP04/]                 |
        |-------------------------------------------------------|
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        +-------------------------------------------------------+
                                                    Page 164


                         NODE TABLE

The node table, pointed to by NODTBL:, contains  a  list  of
all nodes known to TOPS-20, including itself.  This table is
stored in nonresident monitor free space.

Defined in:  STG

Referenced by:  NSPSRV

                                Format

        +-------------------------------------------------------+
        |     Number Of Nodes      |  Maximum Number Of Nodes   |
        |-------------------------------------------------------|
        |  Pointer To Node Name    | Pointer To Nearer Neighbor |
        |-------------------------------------------------------|
        |                          .                            |
        |                          .                            |
        \                          .                            \
        +-------------------------------------------------------+
                                                    Page 165


                           NTCTAB

Network topology change  fork  table.   This  is  the  table
NSPSRV uses to notify user processees of topology changes on
the network.

Defined in:  STG

Referenced by:  NSPSRV

                                 Format

        +-------------------------------------------------------+
NTCTAB: |        Fork number        |     Interrupt channel     | / \
        +-------------------------------------------------------+  |
        |                           .                           |  |
        |                           .                           | NTCMAX
        |                           .                           |  =5
        \                           .                           \  |
        |                           .                           | \ /
        +-------------------------------------------------------+
                                                    Page 166


                           OFNLEN

Open File Length Table.  This non-resident  table,  contains
the current file byte size and file byte count for each open
file.  It is parallel to the OFN areas of the SPT  and  SPTH
tables.

Defined in:  STG

Referenced by:  DISC, JSYSF, PAGEM


                0     5 6                            35
               +---------------------------------------+
               | OFNBSZ| OFNBC                         | / \
        OFNLEN:|Byte Sz|      File Btye Count          |  |
               |---------------------------------------|  
               |                                       | NOFN
               |                                       |  
               |                                       |  |
               |                                       |
               |                                       | \ /
               +---------------------------------------+
                                                    Page 167


                           PHYCHT

PHYSIO Channel Dispatch Tables.   This  table  contains  the
names  of function dispatch tables for all supported channel
types.  Currently supported channel types are the RH20F  and
the  RH11F.   Both  are supported by the same named dispatch
table, RH2DSP, in their respective monitor modules, PHYH2 or
PHYH11.   However, only one of these modules is present in a
given monitor.

Defined in:  STG

Referenced by:  PHYSIO


                                Format


        +-------------------------------------------------------+
PHYCHT: |           Flags           |     Channel Dispatch      |
        |-------------------------------------------------------|
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        |                           .                           |
        +-------------------------------------------------------+



        Note:  This table currently contains only one entry 
               .CTRH2,,RH2DSP
                                                    Page 168


                           PHYUNT

PHYSIO Unit Dispatch Tables.  Table of known  unit  dispatch
routines, (i.e., one for disk and one for magtape).

Defined in:  STG

Referenced by:  PHYH2


                                Format


        +-------------------------------------------------------+
PHYUNT: | Type (DSK)=.UTRP4        | DSK Unit Dispatch Adr.     |
        |                          |         = RH4DSP           |
        |-------------------------------------------------------|
        |  Type (MTA)=.UTTM2       | MTA Unit Dispatch Adr.     |
        |                          |         = TM2DSP           |
        |-------------------------------------------------------|
        | Type (DX20)=.UTDX2       | DX20 Dispatch Adr.         |
        |                          |         = DX2DSP           |
        +-------------------------------------------------------+
                                                    Page 169


                           PIDCNT

Process ID Count Table.  This non%-resident table, holds the
send  quota  and  count and the PID quota and count for each
job.

Defined in:  STG

Referenced by:  IPCF

                                    FORMAT

         0            8 9            17 18         26 27         35
        +----------------------------------------------------------+
PIDCNT: !    PIDSQ     !     PIDSC     !    PIDPQ    !    PIDPC    !  / \
        !     SEND     !     SEND      !     PID     !     PID     !   !
        !    QUOTA     !     COUNT     !    QUOTA    !    COUNT    !   !
        !----------------------------------------------------------!   !
        !                              !                           !   !
        !                              !                           !   !
        !                              !                           !
        !                              !                           ! NJOBS
        !                              !                           !
        !                              !                           !   !
        !                              !                           !
        !                              !                           !  \ /
        +----------------------------------------------------------+
                                                    Page 170


                           PIDTBL

Process ID Table.  This non%-resident table, is a  table  of
halfword  entries, one entry per PID;  the number of entries
in the table is two times the number of jobs.  (The  monitor
is  assuming  an  average of 2 PIDs per job.) If a PID is in
use, the table entry will contain the  address  of  the  PID
header.   PID's  not  in use are linked together;  PIDLST is
the free PID header.

Defined in:  STG

Referenced by:  IPCF

        +-------------------------------------------------------+
        |  ADR of PID Header 1 or   |  ADR of PID Header 2 or   |  / \
        |   Link to Next Free PID   |   Link to Next Free PID   |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | PIDTBS
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                    Page 171


                            PSB

Process Storage Block.  Each  fork  has  a  Process  Storage
Block  which  holds  per-process  information  such as:  the
fork's PC and ACs when not running;  the forks known to this
process,   and   accounting,   PSI,   paging  and  directory
information.

It also holds trapping information and  the  hardware  cells
for  the  fork's User Process Table (See UPT Table).  Page 2
of the PSB houses the push down list  used  by  the  monitor
when executing JSYSs.  (i.e.  in process context).

The PSBMAP map in the PSB points to all of  the  per-process
storage  area  (including the PSB itself).  When the monitor
references the current  fork's  per-process  area,  it  uses
virtual  addresses,  707000-777777.   (The  monitor's mapped
slots in MMAP for virtual pages 707-777 point to the  PSBMAP
via indirect pointers).

Monitor virtual pages in the per-process area are  used  for
the  PSB table, the User's Page Map Table, and IDXFIL.  Some
per-process pages are used temporarily by  the  Swapper  and
Map  routines and by by the Program Software Interrupt (PSI)
and fork utility routines.

Defined in:  STG

Referenced by:  APRSRV, DATIME, DIRECT, DISC, DSKALC, 
                DTESRV, ENQ, FESRV, FILINI, FILMSC, 
                FORK, FREE, GTJFN, IO, IPCF, JSYSA, 
                JSYSF, LINEPR, LOGNAM, MAGTAP, MEXEC,
                PAGEM, PHYSIO, POSTLD, SCHED, SYSERR
                                                    Page 172


                                Format


        +-------------------------------------------------------+ / \
UACB:   |                 Monitor Call AC Stack                 |  |
        |                                                       | N44CB
        |                                                       |  |
        \                                                       \  |
        |-------------------------------------------------------| \ /
JOBNO:  |              Job # to Which Fork Belongs              |
        |-------------------------------------------------------|
JOBBIT: |                  SCHED Control Bits                   |
        |-------------------------------------------------------|
FNPMAX: | Maximum Number of Pages in Working Set for This Fork  |
        |-------------------------------------------------------|
JOBCK0: |        Variables for Scheduler Time Guarantee         |
        |-------------------------------------------------------|
JOBCK1: |        Variables for Scheduler Time Guarantee         |
        |-------------------------------------------------------|
RUNT2:  |      Run Time Fractional Parts of a Millisecond       |
        |-------------------------------------------------------| / \
FKTAB:  \         Local Fork Handle to Job Handle Table         \ NLFKS/2
        \                                                       \  |
        |-------------------------------------------------------| \ /
FORKN:  |  Job Fork # at Top Fork   |         This Fork         |
        |-------------------------------------------------------|
FKRT:   |                     Fork Run Time                     |
        |-------------------------------------------------------|
PRARGP: |             Pointer to Process Arguments              |
        |-------------------------------------------------------|
MPP:    |       Monitor Saved Stack Pointer at Last MENTR       |
        |-------------------------------------------------------|
PRIMRY: |           Primary I/O Indirection Pointers            |
        |-------------------------------------------------------|
SLOWF:  |                 Slow MON Routine Flag                 |
        |-------------------------------------------------------|
INTDF:  |              Defer Interrupts IF .GE. 0               |
        |-------------------------------------------------------|
INTDFF: |               SOS INTDF or JSYS PSISV1                |
        |-------------------------------------------------------|
MJRSTF: |               XJRSTF FFL or JSYS PSISV0               |
        |-------------------------------------------------------|
ACBAS:  |               Current AC Stack Pointer                |
        |-------------------------------------------------------|
ITFFL:  |              Flags on Interrupt to MEXEC              |
        |             (Must be contiguous with ITFPC)           |
        |-------------------------------------------------------|
ITFPC:  |               PC on Interrupt to MEXEC                |
        |-------------------------------------------------------|
TRPID:  |           IDENT of PT or Page Causing Trap            |
        |-------------------------------------------------------|
TRPPTR: |        Storage Address or Pointer Causing Trap        |
        |-------------------------------------------------------| / \
UAC:    |              User ACs (from AC block 1)               | 16
        \                                                       \ \ /
                                                    Page 173


        |-------------------------------------------------------| / \
PAC:    |                      Process ACs                      |  |
        \                                                       \ 16
        |-------------------------------------------------------| \ /
PFL:    |   Process Flags (Must be contiguous with PPC)         |
        |-------------------------------------------------------|
PPC:    |                      Process PC                       |
        |-------------------------------------------------------|
NSKED:  |                   No-Schedule Word                    |
        |-------------------------------------------------------|
RSKED:  |            No-Schedule Trap JFCL/JSR RSKCHK           |
        |-------------------------------------------------------| / \
        |                                                       |  |
TRAPSK: \             Stack Used During Pager Traps             \ NTSK=
        |                                                       |  50
        |-------------------------------------------------------| \ /
TRAPSW: |                   Trap Status Word                    |
        |-------------------------------------------------------|
TRAPAP: |                   Page Trap Saved P                   |
        |-------------------------------------------------------|
TRAPC:  |              Pager Trap Recursion Count               |
        |-------------------------------------------------------|
UTRPCT: |         Count of Pager Traps for This Process         |
        |-------------------------------------------------------|
USWPCT: |        Count of SWPINW Calls for This Process         |
        |-------------------------------------------------------|
PTTIM:  |               Time Spent in Pager Traps               |
        |-------------------------------------------------------|
LSTXGR: |                Time (FKRT) of Last XGC                |
        |-------------------------------------------------------|
FKTLST: |            Lost Time While Clock Turned Off           |
        |-------------------------------------------------------|
CRSKED: |              In Critical Section if Non-0             |
        |-------------------------------------------------------|
SKDFL:  |             Scheduler Temp (Return Flags)             |
        |-------------------------------------------------------|
SKDPC:  |      Scheduler Temp (Return) Must Stay With SKDFL     |
        |-------------------------------------------------------|
MONFL:  |               Temp Monitor PC and Flags               |
        |-------------------------------------------------------|
MONPC:  |                 Must Stay With MONFL                  |
        |-------------------------------------------------------|
PSIPT:  |               PSI Storage List Pointer                |
        |-------------------------------------------------------|
PIOLDS: |           FKSTAT Prior To PSI if was Waiting          |
        |-------------------------------------------------------|
LEVCHN: |          Level Table      |  Channel Table Addresses  |
        |-------------------------------------------------------|
PSISYS: |                Non-0 if PSI System Off                |
        |-------------------------------------------------------|
MONCHN: |             Channels Reserved by Monitor              |
        |-------------------------------------------------------| / \
PIPDB:  |                  PSI Routine Stacks                   |  |
        |                                                       | NPIPDL=
        \                                                       \  31
                                                    Page 174


        |-------------------------------------------------------| \ /
PIAC:   |           Saved User ACs During Break Start           | / \
        \                                                       \  16
        |-------------------------------------------------------| \ /
PSICHA: |             Channel Assigned to TERM Code             | / \
        \                                                       \ NTERMI/16
        |-------------------------------------------------------| \ /
PIMSK:  |     PSI Request Word Being Passed to PSI Service      |
        |-------------------------------------------------------|
PSIBW:  |                  Break Waiting Word                   |
        |-------------------------------------------------------|
FORCTC: |     Channel Which Caused Forced Fork Termination      |
        |-------------------------------------------------------|
PSICHM: |                 Channel Enabled Word                  |
        |-------------------------------------------------------|
SUPCHN: |             Channels Reserved by Superior             |
        |-------------------------------------------------------|
        |              Hardware Storage  (UPT cells)            |
 UPTTPI=|                                                       |
 HWPTA+ |                (see UPT Table Description)            |
   120  |                                                       |
        |                                                       |
        \                                                       \
        |-------------------------------------------------------|
PSIBIP: |            Break in Progress Word (Levels)            |
        |-------------------------------------------------------|
ENSKR:  \                Scheduler Temp (Return)                \
        |-------------------------------------------------------|
ENSKR+3:|                  JRST ENSKED                          |
        |-------------------------------------------------------|
ADRBRK: |                 Address Break Information             |
        |-------------------------------------------------------|
ADRBK1: |      Address of Instruction Causing Address Break     |
        |-------------------------------------------------------|
MONBK:  |            Interrupt to Monitor if Non-zero           |
        |-------------------------------------------------------|
PIFL:   |            Saved Flags (Must be with PIPC)            |
        |-------------------------------------------------------|  / \
PIPC:   |           Saved PC during Initial PI Service          |   3
        \                  (called with XPCW)                   \   |
        |-------------------------------------------------------|  \ /
FKTOFF: |           Time at Which CPU Clock Turned Off          |
        |-------------------------------------------------------|
NWSCE:  |              Number of Entries in WS Cache            |
        |-------------------------------------------------------|
LSTXGT: |                Time (TODCLK) of Last XGC              |
        |-------------------------------------------------------|
SYMPAG: |         Page Used by MDDT for Mapping Symbols         |
        |-------------------------------------------------------|
UTRSW:  |                  Saved TRAPSW for User                |
        |-------------------------------------------------------|
UMUUOW: |                 Save MUUO Word for User               |
        |-------------------------------------------------------|
KIMUU1: |                 Last UUO Word from User               |
        |-------------------------------------------------------|
                                                    Page 175


PSLEVT: |              Address of User's Level Table            |
        |-------------------------------------------------------|
PSCHNT: |             Address of User's Channel Table           |
        |-------------------------------------------------------|
PSBITS: |             Miscellaneous Per Process Bits            |
        |-------------------------------------------------------|
TRPDSP: |             Dispatch for MON ILLEG MEM REF            |
        |-------------------------------------------------------|
DRLOC:  |         Location in Directory During Searches         |
        |-------------------------------------------------------|
DRINP:  |          Pointer to Input Name During Lookup          |
        |-------------------------------------------------------|
DRINL:  |                Length of Input String                 |
        |-------------------------------------------------------|
DRMSK:  |         Mask of 0 Bits in Last Word of String         |
        |-------------------------------------------------------|
DRSCN:  |           Pointer to FDB Link During Lookup           |
        |-------------------------------------------------------|
        |0                    17|18     |19                   35|
DROFN:  |DRLFDB                 |DRROF  |DIROFN                 |
        |  Last FDB Checked by  |Release|OFN of Current Mapped  |
        |   FDBCHK              | OFN   | Directory             |
        |-------------------------------------------------------|
DRMAP:  |              Adr of Map Page when SEC2                |
        |-------------------------------------------------------|
DIRCAD: |             Cache Address of Last MAPDIR              |
        |-------------------------------------------------------|
IDXMAP: | Adr of IDX Tbl. Pg Map When Extended Addressing       |
        |-------------------------------------------------------|
        |0                    17|18     |19                   35|
STRINF: |CURUC                  |IDXFLG |CURSTR                 |
        | Unique Code of        |XB File| Str. No. of Cur.      |
        | Currently Mapped Index| Mapped|  Mapped Index File    |
        | File                  |       |                       |
        |-------------------------------------------------------|
ENTVEC: |                 Entry Vector Pointer                  |
        |-------------------------------------------------------|
PATADR: |           10/50 Compatability Entry Vector            |
        |-------------------------------------------------------|
PATU40: |      Where to Store C(40), Setup as UMOVEM 1,XX       |
        |-------------------------------------------------------|
PATUPC: |       Where to Store PC, Setup as UMOVEM 1, XX        |
        |-------------------------------------------------------|
DMSADR: |                   DMS Entry Vector                    |
        |-------------------------------------------------------|
DMSU40: |           Where to Store C(40) on DMS Call            |
        |-------------------------------------------------------|
DMSUPC: |             Where to Store PC of DMS Call             |
        |-------------------------------------------------------|
CABMSK: |                   Capability Mask                     |
        |-------------------------------------------------------|
CAPENB: |                Capabilities Enabled                   |
        |-------------------------------------------------------|
SNPPGS: |          Count           | Page # of First Page Locked|
        |                          | Down for Snooping          |
                                                    Page 176


        |-------------------------------------------------------|
SNPLST: |          Flags           | Link to 1st BP for Fork    |
        |-------------------------------------------------------|
LSTERR: |                   Last Error Number                   |
        |-------------------------------------------------------| / \
ERRSAV: \               Block of Error Parameters               \ NERRSV=4
        |-------------------------------------------------------| \ /
        |                                                       | / \
PSBMAP: |                 Map for Process Area                  |  |
        \                                                       \ PSBMSZ
        |                                                       |  |
        |                                                       |  |
        |-------------------------------------------------------| \ /
JTBLK:  |               FKJTB + forkn for this fork             |
        |-------------------------------------------------------|
JTLCK:  |        Lock on JSYS Trap to Monitor (this) fork       |
        |        Lock Protects JTTRW and Allows Only one        |
        |     JSYS Trap Interrupt at a Time to This Monitor     |
        |-------------------------------------------------------|
JTTRW:  |        JSYS Trap Word (Set by interrupting fork)      |
        |             Contains trapping instruction             |
        |-------------------------------------------------------|
JTTFK:  |                         |JTFRK                        |
        |                         |  Forkn of Trapping Fork     |
        |-------------------------------------------------------|
        |              |12      17|                             |
JTMNW:  |              | JTMCN    | JTNMI                       |
        |              | Monitor's|  Forkn of Mon Interrupted   |
        |              | PSI Chan | (PSI'd)                     |
        |-------------------------------------------------------|
PNSKDC: |   NOSKED's Done by DIAG & other Resource Managers     |
        |-------------------------------------------------------|
ARTHTR: |            User-Specified Arithmetic Trap             |
        |-------------------------------------------------------|
CRTRGN: |               Indicates Critical Region               |
        |-------------------------------------------------------|
STRWRD: |  STRFLG                 | NOSTR                       |
        |     Flag for STR Info   |   # Mount Count Increments  |
        |                         |    (for KSELF)              |
        |-------------------------------------------------------|
FKXORA: |        Fork IDXORA During Creation of Structure       |
        |-------------------------------------------------------|
        \ / / / / / / / / / / / / / / / / / / / / / / / / / / / \
        |-------------------------------------------------------| / \
WSCSH:  |           (Begins at Top of Second PSB Page)          |  |
        \                   Working Set Cache                   \ WSCHCW=
        \                                                       \  128
        |                                                       |  |
        |-------------------------------------------------------| \ /
        \ / / / / / / / / / / / / / / / / / / / / / / / / / / / \
        |-------------------------------------------------------|  ^
UPDL:   |               User PDL for Monitor Calls              |  |
        \      UPDL is Defined as the End of this Page NUPDL    \ NUPDL
        |                                                       |  |
        +-------------------------------------------------------+  v
                                                    Page 177


                           PTYSTS

Pseudo Terminal Status Table.  This table contains the PTY's
status word.

Defined in:  STG

Referenced by:  FILMSC

Index:  PTY Number


                                Format


        +-------------------------------------------------------+
PTYSTS: |                    PTY Status Bits                    |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   
        |                           .                           | NTTPTY
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                    Page 178


                          Q-BLOCK

Queue Block.  The information for each ENQ request is stored
in a Q-BLOCK.  QBLOCK's are doubly linked for each job;  the
list header is in the right  half  of  ENQLST  in  the  JSB.
Also,  QBLOCK  are  doubly  linked on a system wide list for
each lock block;  the list header is in the lock block.

Defined in:  ENQ

Referenced by:  ENQ

                                  Format
         0                        17 18                       35
        +-------------------------------------------------------+
        |  ENQLJQ                   |  ENQNJQ                   |
      0 |      Back Pointer To      |    Forward Pointer To     |
        |   Last Q-Block For Job    |   Next Q-Block For Job    |
        |-------------------------------------------------------|
        |  ENQLLQ                   |  ENQNLQ                   |
      1 |     Back Pointer To       |    Forward Pointer To     |
        |       Last Q-Block        |       Next Q-Block        |
        |-------------------------------------------------------|
        |  ENQFLG       11| ENQCHN  |  ENQFRK                   |
      2 |      Flags      |   PSI   |     Fork to Interrupt     |
        |Either Lock or Q | Channel |  When Request is Locked   |
        |-------------------------------------------------------|
        |  ENQNR                    |  ENQID                    |
      3 |      # of Resources       |      Request ID Code      |
        |    Requested From Pool    |                           |
        |-------------------------------------------------------|
        |  ENQLRQ                   |  ENQFQ                    |
      4 |      Back Pointer To      |    Forward Pointer To     |
        |  Last Q-Block of Request  |  Next Q-Block of Request  |
        |-------------------------------------------------------|
        |  ENQLBP                   |  ENQGRP                   |
      5 |        Pointer to         |        Group # For        |
        |   Lock-Block of this Q    |     Sharable Requests     |
        |-------------------------------------------------------|
        |  ENQNST                   |  ENQJFN                   |
      6 |        Nest Count         |      JFN of Request       |
        |                           |     or -1, -2, or -3      |
        |-------------------------------------------------------|
        |                           |  ENQMSK                   |
      7 |                           |      Pointer to the       |
        |                           |        Mask Block         |
        +-------------------------------------------------------+
                                                    Page 179


         0         11 12        17 18                         35
 Word 2 +-------------------------------------------------------+
        |     ||||||| ENQCHN      | ENQFRK                      |
        |     ||||||| PSI Channel |  Fork to interrupt when     |
        |     |||||||             |  request is locked          |
        +-------------------------------------------------------+


       Symbol     Bits    Pointer       Meaning

     EN.LTL=40      6                   Long Term Block
     EN.INV=20      7                   This Q%-Block is invisible
     EN.LOK=10      8                   The Q%-Block has the Lock
                                         locked.
     EN.TXT=4       9                   This Block has a Text
                                         String Identity.
     EN.EXC=2      10                   Request is Exclusive
     EN.LB=1       11                   This is the Lock%-Block
                  13%-17   ENQCHN        PSI Channel (%-1 means job
                                         blocked)
                  18%-35   ENQFRK        Fork # of Creator of
                                         Q%-Block
                                                    Page 180


                       RES-FREE-SPACE

Resident  Free  Space  Storage.   This  area  contains   the
resident free space bit table, RESBTB, which indicates which
4-word blocks of the resident free space pools are in use.

The resident free space (in RESFRP) is pooled by PHYSIO  for
building UDBs, CDBs, KDBs, and SDBs;  by TTYSRV for terminal
messages and line dynamic data blocks;   by  NETSRV  for  an
input  and output buffer for each active line;  and by TIMER
for the TIMER JSYS when it builds  a  job's  run-time  limit
block.  (See JOBRTL table).

This area also contains a resident free space  usage  table,
RESUTB,  which  indexed  by pool #, holds the amount of free
space left for each pool.

Defined in:  STG

Referenced by:  DSKALC, FREE, FESRV, NSPSRV, PHYSIO,
                TIMER, TTYSRV
                         Format

        +-------------------------------------+
RESMIN: |       Min Level for All But         |
        |         Level 1* Reqests            |
        |-------------------------------------|
RESAVE: | Average Amount of Free Space Locked |
        |-------------------------------------|
UPRSAV: |      Limit for Job 0 Activity       |
        |-------------------------------------|
RESFRE: |       Count of Free Blocks Left     |
        |-------------------------------------|
RESFFB: |        First Free 4-Word Block      |
        |-------------------------------------|
RESIFL: |          Initialization Flag        |
        |          (-1 During Startup)        |
        |-------------------------------------|
RESBTB: |                  .                  | / \
        |                  .                  |  |
        |                  .                  | RESQTL
        \   Resident Free Space Bit Table     \  |
        |-------------------------------------| \ /
RESBAS: | Base Adr of the Resident Free Pool  |
        |-------------------------------------| / \
RESUTB: |   Resident Free Space Usage Table   |  |
        |         (indexed by pool#)          |  |
        \                                     \ RESQTL
        |                                     |  |
        |                                     |  |
        +-------------------------------------+ \ /
                                                    Page 181


  The following storage is in the non-resident area of the
  monitor.


        +-------------------------------------+ / 
RESFRP  |                                     |  |
        \                                     \ NRESFP
        \      Resident Free Space Pools      \ *PGSIZ
        |                                     |  |
        |                                     |  |
        +-------------------------------------+  /

  *Note:  Requests for Resident Free Space are given
          priority levels where:

          Level 1 - Has highest priority and monitor
                    always tries to assign space.  Page
                    faults are not allowed.
          Level 2 - Has second level priority where
                    monitor will not assign space if
                    free storage would go below RESMIN.
                    Page faults are not allowed.
          Level 3 - Has lowest priority and requests for
                    this level are made in process con-
                    text.  Page Faults are allowed.
                                                    Page 182


                           SCDRQB

Scheduler Request Table.  During the scheduler's overhead
cycle, the initial job startup request is placed in this
table when the first CTRL/C is processed.  The table is
later examined in the same cycle and all entries are
processed by dispatching to each entry's dispatch address.

Defined in:  SCHED

Referenced by:  SCHED, TTYSRV


                                Format


        +-------------------------------------------------------+ / \
SCDRQB: |           Data            |     Dispatch Address      |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           | NSCDRQ
        |                           .                           | = 33
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \  |
        |                           .                           |  |
        +-------------------------------------------------------+ \ /
                                                    Page 183


                      SCHED-VARIABLES

This storage  contains  the  variables  used  in  the  SCHED
module.   It  contains pointers to the GOLST and to the wait
lists.  Clock and other parameters needed for scheduling are
also contained.

Defined in:  STG

Referenced by:  SCHED

                                  Format

        +-------------------------------------------------------+
SKDPDL: |                  Scheduler local PDL                  | / \
        |                                                       | NSKDP
        |                                                       |  =110
        \                                                       \ \ /
        +-------------------------------------------------------+
SCKATM: |         Alarm time - min. of all SCHED clocks         |
        +-------------------------------------------------------+
OLDTCK: |  Alarm time - old time - used to calculate interval   |
        +-------------------------------------------------------+
PISC7R: |                                                       | / \
        |                                                       |  4
        |                                                       |  |
        \                                                       \ \ /
        +-------------------------------------------------------+
PI7AC1: |                    Temps at PISC7                     | / \
        |                                                       |  2
        |                                                       | \ /
        +-------------------------------------------------------+
ALARMT: |             Min. time of forks on clklst              |
        +-------------------------------------------------------+
SKDTHS: |            Time in SCHED so far this pass             |
        +-------------------------------------------------------+
SKDLST: |               Last reading of HP clock                |
        +-------------------------------------------------------+
SKDLRT: |      Runtime of last trip thru scheduling cycle       |
        +-------------------------------------------------------+
SNPSV1: | Place to save AC while ck'ing PC for SNOOP break pt.  |
        +-------------------------------------------------------+
FORKX:  |            Index of currently running fork            |
        +-------------------------------------------------------+
FREJOB: |             Pointer to list of free jobs              |
        +-------------------------------------------------------+
WTLST:  |             Pointer to waiting fork list              |
        +-------------------------------------------------------+
WT2LST: |    Pointer to waiting forks to be waked by UNBLK1     |
        +-------------------------------------------------------+
TTILST: |    Pointer to list of forks waiting for TTY input     |
        +-------------------------------------------------------+
TTOLST: |         Pointer to list of TTY output events          |
        +-------------------------------------------------------+
FRZLST: |        Pointer to list waiting for unfreezing         |
                                                    Page 184


        +-------------------------------------------------------+
TRMLST: | Pointer to list waiting for inferior fork termination |
        +-------------------------------------------------------+
CLKLST: |           Pointer to list waiting for Clock           |
        +-------------------------------------------------------+
JTLST:  |                   JSYS traps queue                    |
        +-------------------------------------------------------+
JTLSTL: |Linked list of forks wait on JTLCK to PSI some mon fork|
        +-------------------------------------------------------+
GOLST:  |             Pointer to runnable fork list             |
        +-------------------------------------------------------+
JB0FLG: |                   Run JOB 0 request                   |
        +-------------------------------------------------------+
FRECB:  |                 Free core number bits                 |
        +-------------------------------------------------------+
FREFK:  |                  List of free forks                   |
        +-------------------------------------------------------+
SYSIFG: |         System has been initialized if not 0          |
        +-------------------------------------------------------+
PWRDWN: |    Power failure detected if .g. 0, done if .l. 0     |
        +-------------------------------------------------------+
RLODPC: |               PCs for keep alive reload               | / \
        |                                                       |  4
        |                                                       |  |
        \                                                       \ \ /
        +-------------------------------------------------------+
FPTABL: |          PAGEM dispatch for section numbers           | / \
        |                                                       | MAXSEC
        |                                                       |  +1
        \                                                       \ \ /
        +-------------------------------------------------------+
NBPROC: |          Number of processes in balance set           |
        +-------------------------------------------------------+
NBWT:   |        Number waiting processes in balance set        |
        +-------------------------------------------------------+
NBSWP:  |             Number of forks in swap wait              |
        +-------------------------------------------------------+
MAXBP:  |           Max number of jobs in balance set           |
        +-------------------------------------------------------+
BSQNT0: |        Value of BSQNT at start of last running        |
        +-------------------------------------------------------+
SUMNR:  |     Sum of reserve pages, all processes in memory     |
        +-------------------------------------------------------+
SUMBNR: |          Sum of working sets in balance set           |
        +-------------------------------------------------------+
NWSEPG: |          Number pages WSETs entering memory           |
        +-------------------------------------------------------+
BALSHC: |   Count of pages in balance set because of sharing    |
        +-------------------------------------------------------+
NXTCNF: |               Next fork to check - GCNO               |
        +-------------------------------------------------------+
RELCB:  |    Mask of core numbers released but not cleared      |
        +-------------------------------------------------------+
MAXNR:  |                  Max value of SUMNR                   |
        +-------------------------------------------------------+
                                                    Page 185


MAXHNR: |          Max NR of balance set holding forks          |
        +-------------------------------------------------------+
BSLST:  |     Pointer to list of balance set holding forks      |
        +-------------------------------------------------------+
NBSL:   |          Number of balance set holding forks          |
        +-------------------------------------------------------+
NEBAL:  |     Number of processes now entering balance set      |
        +-------------------------------------------------------+
REMFGS: |              Flags set on REMBSJ/REMBSF               |
        +-------------------------------------------------------+
NPMAX:  |      Max number of pages in core for one proces       |
        +-------------------------------------------------------+
SNPMAX: |           Small NPMAX for loaded conditions           |
        +-------------------------------------------------------+
IRJAV:  |                Nearest integer to RJAV                |
        +-------------------------------------------------------+
WSMTIM: |                  Time for next WSMGT                  |
        +-------------------------------------------------------+
RWSOKF: |                 Flag - OK to do REMWS                 |
        +-------------------------------------------------------+
NWSMEM: |                   Number WS in mem                    |
        +-------------------------------------------------------+
NHQFK:  |               Number forks on non-maxq                |
        +-------------------------------------------------------+
NLQFK:  |                 Number forks on maxq                  |
        +-------------------------------------------------------+
SCHFLG: |              Permanent scheduling flags               |
        +-------------------------------------------------------+
SKEDF1: |           Start process via CH7 break in 1            |
        +-------------------------------------------------------+
SKEDF3: |              Process clock counted to 0               |
        +-------------------------------------------------------+
SKEDFC: |         Force clear of balance set and memory         |
        +-------------------------------------------------------+
INSKED: |               In scheduler if non-zero                |
        +-------------------------------------------------------+
SSKED:  |              Last job running was NOSKED              |
        +-------------------------------------------------------+
SETPAG: |            Temp for setting pager at SCDR             |
        +-------------------------------------------------------+
RSKCHK: |                   XPCW destination                    | / \
        |                                                       |  4
        |                                                       |  |
        \                                                       \ \ /
        +-------------------------------------------------------+
PSKED:  |                Page transfer completed                |
        +-------------------------------------------------------+
QSKED:  |          Blocked fork now unblocked if .g. 0          |
        +-------------------------------------------------------+
TSKED:  |             TTU output event if non-zero              |
        +-------------------------------------------------------+
BSKED:  |      Fork voluntarily left balance set if .g. 0       |
        +-------------------------------------------------------+
NGOJOB: |                Number of runnable jobs                |
        +-------------------------------------------------------+
                                                    Page 186


RJTTIM: |             Time at last update to RJTSUM             |
        +-------------------------------------------------------+
RJATIM: |               Time of next RJAV update                |
        +-------------------------------------------------------+
RJAVS1: |              RJTSUM at last RJAV update               |
        +-------------------------------------------------------+
RJAVS2: |              HQFSUM at last RJAV update               |
        +-------------------------------------------------------+
RJAVS3: |              LQFSUM at last RJAV update               |
        +-------------------------------------------------------+
BSQNT:  |             Running job remaining quantum             |
        +-------------------------------------------------------+
TIM1:   |                   SCHED fast clock                    |
        +-------------------------------------------------------+
TIM2:   |                     Second clock                      |
        +-------------------------------------------------------+
FKT0:   |               Clock at start of running               |
        +-------------------------------------------------------+
FKT1:   |                 Time used since SETRT                 |
        +-------------------------------------------------------+
TIM0:   |                 TODCLK atlast C1STAT                  |
        +-------------------------------------------------------+
SCDRQI: |                  SCHED request queue                  |
        +-------------------------------------------------------+
SCDRQO: |                                                       |
        +-------------------------------------------------------+
SCDRQB: |                                                       | / \
        |                                                       | NSCDRQ
        |                                                       |  =33.
        \                                                       \ \ /
        +-------------------------------------------------------+
TODCLK: |      Millisecond clock, monotonically increasing      |
        +-------------------------------------------------------+
TODPWL: |     Time of day (in seconds) by power line clock      |
        +-------------------------------------------------------+
CHKTIM: |        Time at which JOB 0 considered overdue         |
        +-------------------------------------------------------+
SCDRN1: |              Run only job N if n .g. -1               |
        +-------------------------------------------------------+
                                                    Page 187


                            SDB

Structure  Data  Block.   This  block,  one  per  structure,
contains  information  about  the  structure's units, master
directory (i.e.  Root%-Directory), bit  map  for  disk  page
allocation/deallocation,  and  assigned  swapping  area.  It
also contains mount and open%-file information.   SDBBLO  is
the  name  of the storage area reserved for handling the SDB
for the Public Structure (PS).

Defined in:  STG

Referenced by:  DEVICE, DIRECT, DSKALC, FILINI, FUTILI, IO, 
                PHYSIO, JSYSA, JSYSF, MEXEC, MSTR

                                Format

        +-------------------------------------------------------+
        | STRNAM                                                |
SDBNAM=0|              Structure Name (in SIXBIT)               |
        |-------------------------------------------------------|
        | STRNUM                                                |
SDBNUM=1|             Number of Units in Structure              |
       .|-------------------------------------------------------|
       .| STRSIZ                                                |
SDBSIZ .|         Size (in sectors) of Each Unit in Structure   |
        |-------------------------------------------------------|
        | STRSTS                    | STRJB                     |*
SDBSTS  |          Status Flags     |            Initing Fork # |
        |-------------------------------------------------------|
        | STRRXB                                                |
SDBRXB  |         Address of Root Directory Index Block         |
        |-------------------------------------------------------|
        | STRBXB                                                |
SDBBXB  | Address of Backup Copy of Root Directory Index Block  |
        |-------------------------------------------------------|
        | STRNSS                                                |
SDBNSS  |          Number of Swapping Sectors per Unit          |
        |-------------------------------------------------------|
        | STRFSS                                                |
SDBFSS  |            First Swapping Sector per Unit             |
        |-------------------------------------------------------|
        | STRBTB                                                |
SDBBTB  |                   OFN of Bit Table                    |
        |-------------------------------------------------------|
        | STRFC                                                 |
SDBFRC  |           Count of Free Pages on Structure            |
        |-------------------------------------------------------|
        | STRRDO                    | STRIDX                    |
SDBIDX  |   OFN of Root Directory   |   Handle of Index Table   |
        |-------------------------------------------------------|
        | STRLDN                                                |
SDBLDN  |         Last Directory Number on This Structure       |
        |-------------------------------------------------------|
        | STRLCA                                                |
                                                    Page 188


SDBLCA  |           Last Cylinder Assigned by DSKASN            |
        |-------------------------------------------------------|
        | STRCYL                                                |
SDBCYL  |             Total Cylinders in Structure              |
        |-------------------------------------------------------|
        | STRB0                                                 |
SDBBT0  |            Length of Top Half of Bit Table            |
        |-------------------------------------------------------|
        | STRB1                                                 |
SDBBT1  |          Length of Bottom Half of Bit Table           |
        |-------------------------------------------------------|
        | STRTYP                                                |
SDBTYP  |         Address of DSKSIZ Table for This Type of Disk |
        |-------------------------------------------------------|
        | STRUC               |STRUS| STRLK                     |
SDBFLK  |  Unique Code in SDB |Str #| File Lock Count           |
        |-------------------------------------------------------|
        | STRMC                     | STROF                     |
SDBCNT  |        Mount Count        |      Open File Count      |
        |-------------------------------------------------------|
        | STRMI                                                 |
SDBPUC  |       Pack Unique Code for Media Identification       |
        |-------------------------------------------------------|
SDBOMF  |                                                       |
        |       Original Minimum Free Page Limit                |
        |-------------------------------------------------------|
SDBMXF  |                                                       |
        |       Boundary Above Which SDBMFP=SDBOMF              |
        |-------------------------------------------------------|
SDBMFP  |                                                       |
        |   Min. Free Pgs. below which DSKASA Changes           |
        |              Assignment Algorithm                     |
        |-------------------------------------------------------| / \
        | STRUDB                                                |  |
SDBUDB  |           Flags                  Pointer to UDB       |  |
        |             .             |             .             | MXSTRU
        |             .             |             .             |  |
        \             .             |             .             \  |
        +-------------------------------------------------------+ \ /
                                                    Page 189




         0 1 2 3                  15 16 17 18                       35
        +-------------------------------------------------------------+
SDBSTS  | | | |                     |  |  |                           |
        +-------------------------------------------------------------+


            Symbol      Bits     Pointer     Content

            MS%PS        0       STPS        Structure is public
            MS%DIS       1       STDIS       Structure is being dismounted
            MS%DOM       2       STDOM       Structure is domestic
            MS%NRS       6       STNRS       Structure is not regulated
                        16       STIDX       Index table file OFN has been
                                              set up
                        17       STCRD       Creating Root Directory on
                                              this Structure
                       18%-35     STRJB       Initializing job # (only legal
                                              user while structure is being
                                               initialized)
                                                    Page 190


                           SNAMES

Subsystem Names.  Each entry contains  a  subsystem  program
name.

Defined in:  STG

Referenced by:  MEXEC


                                Format

        +-------------------------------------------------------+ / \
SNAMES: |                     SIXBIT/Name/                      |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           | NNAMES
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        +-------------------------------------------------------+ \ /
                                                    Page 191


                           SNBLKS

Subsystem Blocks.  Each entry contains the number of  blocks
for a subsystem program.  This table is parallel to SNAMES.

Defined in:  STG

Referenced by:  MEXEC


                                Format


        +-------------------------------------------------------+ / \
SNBLKS: |                   Number of Blocks                    |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           | NNAMES
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        +-------------------------------------------------------+ \ /
                                                    Page 192


                           SPFLTS

Subsystem Page Faults.  Each entry contains the  accumulated
number  of  page  faults  of a subsystem program.  This is a
parallel table to SNAMES.

Defined in:  STG

Referenced by:  MEXEC, PAGEM


                                Format


        +-------------------------------------------------------+ / \
SPFLTS: |                Accumulated Page Faults                |  !
        |-------------------------------------------------------|  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           | 
        |                           .                           | NNAMES
        |                           .                           |  
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        |                           .                           |  !
        +-------------------------------------------------------+ \ /
                                                    Page 193


                            SPT

Special Pages Table.   This  table  is  pointed  to  by  the
firmware's  SPT Base Register (an AC in an AC Block reserved
for hardware/firmware  registers)  which  is  setup  by  the
monitor at system initialization time.  

It is referenced  directly  by  the  paging  firmware  (bits
12%-35  only)  when  virtual to physical address translation
takes place and shared and indirect pointers are involved.  

The first part of the table (of  length  NOFN)  is  used  to
point  to index blocks in memory (or swapping area) for open
files and an index into this part is often referred to as an
OFN  (Open File Number).  The remainder of the table is used
to point to PSBs, JSBs, UPTs, UPTAs, (User Page Map Tables),
and shared file pages.  

The ALOCX value in the OFN area is used as an index into the
allocation  tables (ALOC1 ACOC2) to obtain information about
the directory of the open file, (i.e., pages left in quota).
The  share  count  in the non - OFN area is indexed for each
sharing of the page.

Defined in:  STG, PROLOG

Referenced by:  APRSRV, DISC, DSKALC, FORK, PAGEM, SCHED
                                                    Page 194



                                Format

        +-------------------------------------------------------+
SPT:    |0 ALOCX        11|12 STGADR                          35|  / \  ^
        |    Index into   |         Storage Address             |   |   |
        | Allocation TBL  |         (Index Block Page)          |   |   |
        |-------------------------------------------------------|   |   |
        |                            .                          |   |   |
        |                            .                          |       |
        |                                                       | OFN # |
        |                                                       |       |
        |                                                       |   |   |
        |                                                       |   |   |
        |                                                       |  \ /  |
        |-------------------------------------------------------|       |
        | SPTSHC        11|12   STGADR                        35|       |
        |  Shared Count   |           Storage Address           |       |
        |                 | (Shared File Pg/Ovhd Pg/Page of     |     SSPT
        |                 |           another Pg Tbl            |    (2560)
        |-------------------------------------------------------|       |
        |                            .                          |       |
        |                            .                          |       |
        |                            .                          |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        |                                                       |       |
        +-------------------------------------------------------+       v
                                                    Page 195


                     Storage Address

        Symbol   Bits   Pointer      Contents

                12-35   STGADR       Storage address
                                     (Interpretation follows)
        NCORTM  12-17                Non-Core Test Mask yielding
                                     type of storage.
                                     Bits <12-17>=0 =>
                                     Bits <18-35>=Memory Pg Adr.
                                     Bits <12-17>=0 =>
                                     Bits <18-35>=Drum/DSK Adr.
        DSKAB     14                 Storage address is a disk
                                     address
        DSKNB     15                 Temporary bit used with
                                     DSKAB to say that disk
                                     address is newly assigned. 
        DRMAB    16-17               Storage address is a drum
                                     address
        DRMOB     17                 Used with DRMAB to indicate
                                     that the swapping area has
                                     overflowed to the disk file
                                     system.  (Since TOPS-20 cur-
                                     rently uses only the disk file
                                     system for swapping, a drum
                                     storage address will always 
                                     have bits 16 & 17 set.)
        UAABC    17&35               Temporary bit used by the
                                     monitor's page trap handler
                                     when a copy-on-write page
                                     trap has occurred.  If the
                                     page to be copied is a drum
                                     address, it will be faulted
                                     in before these bits are used,
                                     avoiding conflict over bit
                                     17.  These bits will signify
                                     to a lower level routine,
                                     SWPIN, that the page just
                                     gotten from the free list
                                     has no backup address and 
                                     that it is to get a copy of
                                     another page.
                                                    Page 196


                            SPTH

Special Pages Table Home Information.  This table,  parallel
to  the  SPT table is referenced only by the software and is
divided into two parts.  The first part, indexed by OFN,  is
used  to  point to the home address of each open file (i.e.,
to its index block) and to  hold  status  information  about
each OFN.

The second part is used mainly to show  the  page's  origin.
For a shared file, this is indicated by OFN ,, Page Number ,
where page number is within open file, OFN.  For PSBs, JSBs,
and  UPTs, the SPTH word contains 0 ,, Fork Index.  The free
slots in this part are on a list  chained  through  the  SPT
where the free list pointer resides in FRESPT.

Defined in:  STG

Referenced by:  DISC, DSKALC, FILINI, FORK, PAGEM, PHYSIO


                                Format

        +-------------------------------------------------------+
SPTH:   |       Flags         |Home (DSK)Address of Index Block |* / \ / \
        |-------------------------------------------------------|   |   |
        |                           .                           |   |   |
        |                           .                           | OFN # |
        \                           .                           \   |   |
        |                           .                           |   |   |
        |                           .                           |  \ /  |
        |-------------------------------------------------------|       |
        |            OFN            |        Page Number        |      SSPT
        |-------------------------------------------------------|       |
        |                          or                           |       |
        |-------------------------------------------------------|       |
        |             0             |        Fork Index         |       |
        |-------------------------------------------------------|       |
        |                           .                           |       |
        \                           .                           \       |
        +-------------------------------------------------------+      \ /
                                                    Page 197


           0 1 2 3 4 5 6 7 8 9 0 1 2                                     35
          +----------------------------------------------------------------+
     SPTH | | | | | | | | | | | | | |             Address of Index Block   |
     OFN  +----------------------------------------------------------------+
     entry

          Symbol         Bits         Content
        
          FILWB            1          File write bit in SPTH and ASOFN
                                      argument
          THAWB            2          Thawed bit
          FILNB            3          "File new" bit
          SPTLKB           4          LH of SPTH(OFN), XB(Index Block)
                                      in use by DDMP
          OFNWRB           5          OFN has been modified
          OFNBAT           6          Index block contains a bad block
          OFNERR           7          Error in file (i.e., MPE)
          OFNDMO           8          OFN is on a dismounted structure
          OFNDUD           9          Suppress DDMP
          OFN2XB          10          Second level XB
          SPAREH          11          Spare bit


If a file is OPENed with thawed access (OF%THW), then both 
FILWB and THAWB will be set to 1.  If OPEN'ed with restricted
access, then the THAWB bit will be on and the FILWB will be
off.






         Note:  A file is opened by searching the OFN part of SPTH for the
                index block address. If the address is found and the write
                and thawed bits are legal, it is a shared opening and the 
                same index is used.  If the address is not found, a new
                entry is made from one of the free (%-1) slots in SPTH.
                                                    Page 198


                            SPTO

Special Pages Table O.  This table is parallel  to  the  OFN
area  of the SPT table and contains the structure number and
open file share count for each open  file.   The  OFN  share
count  is  indexed for each opening of the file and for each
shared page within the open file.

Defined in:  STG

Referenced by:  PAGEM

Index:  OFN Number


                                Format


        +-------------------------------------------------------+  / \
        |  OFNSHC                   |  STRX                     |   |
SPTO:   |      OFN Share Count      |        Structure #        |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  NOFN
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        \                           .                           \   |
        |                           .                           |   |
        +-------------------------------------------------------+  \ /

       Symbol      Bits     Pointer      Content

       OFNSCH      0-17                  Share count for an OFN
                    17      OFSHR        One unit of OFN share entry
       STRX       18-35     STX          Structure index (number)
                                                    Page 199


                           SSIZE

Subsystem Working Set Size.  Each entry contains the working
set  size  integral  for  a  subsystem  program.   This is a
parallel table to SNAMES.

Defined in:  STG

Referenced by:  MEXEC, SCHED


                                Format


        +-------------------------------------------------------+ / \
SSIZE:  |               Working Set Size Integral               |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  
        |                           .                           | NNAMES
        |                           .                           |  
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \  |
        |                           .                           |  |
        +-------------------------------------------------------+ \ /
                                                    Page 200


                           STIMES

Subsystem Runtimes.  Each  entry  contains  the  accumulated
runtime of a subsystem program.  This is a parallel table to
SNAMES.

Defined in:  STG

Referenced by:  MEXEC, SCGED

        
                                Format


        +-------------------------------------------------------+ / \
STIMES: |                  Accumulated Runtime                  |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |
        |                           .                           | NNAMES
        |                           .                           |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        \                           .                           \  |
        |                           .                           |  |
        +-------------------------------------------------------+ \ /
                                                    Page 201


                           STRTAB

Structure Data Block Table.  This table contains pointers to
each structure data block in the system.

Defined in:  STG

Referenced by:  DEVICE, DIRECT, DISC, DSKALC, FILINI, FUTULI
                IO, JSYSA, JSYSF, MEXEC, MSTR, PAGEM, PHYSIO
                SWPALC

Index:  Structure Number


                                Format


        +-------------------------------------------------------+
STRTAB: |                    Pointer to SDB                     |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | STRN =
        |                           .                           |  16
        |                           .                           |   
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+
                                                    Page 202


                      SWAP-FREE-SPACE

Swappable Free Space Pool Format.  This table describes  the
header  area that is used in the assignment and deassignment
of swappable free space (by ASGFRE) and the  usage  of  this
space when assigned.

Defined in:  STG

Referenced by:  FREE, IPCF, LOGNAM


                                 Format

        +-------------------------------------------------------+ / \
SWPFRE: |   Adr of 1st Free Block   |          Unused           |  |
        |-------------------------------------------------------|  |
        |                  Lock on Free Space                   |  |
        |-------------------------------------------------------|  |
        |                     Space Counter                     |  |
        |-------------------------------------------------------|  |
        |                Most Common Block Size                 |  7
        |-------------------------------------------------------|  |
        |   Max Top of Free Area    |    Bottom of Free Area    |  |
        |-------------------------------------------------------|  |
        |                 Temporary Work Space                  |  |
        |-------------------------------------------------------|  |
        |                 Temporary Work Space                  |  |
        |-------------------------------------------------------| \ /
SWFREE: |                    Free Space Pool                    | / \
        |                                                       |  |
        |        Space for the Assignment of:                   |  |
        |          PID Headers & Messages                       |  |
        |          ENQ/DEQ Blocks                               |  |
        |          System Wide Logical Name List and            | SWFREL
        |            Definitions Blocks                         |  |
        |          USAGE JSYS Blocks                            |  |
        |          Checkpoint Records                           |  |
        |          Network Strings                              |  |
        +-------------------------------------------------------+ \ /
                                                    Page 203


                           SYNMTB

System Logical Name Table:  This table contains pointers  to
the initial ASCIZ strings for the system logical names.

Defined in:  STG

Referenced by:  LOGNAM


                                  FORMAT

          +-------------------------------------------------------+
 SYNMTB:  | XWD[ASCIZ/SYS/],[ASCIZ/PS:<SUBSYS>/]                  |
          |-------------------------------------------------------|
          | XWD[ASCIZ/HLP/],[ASCIZ/SYS:/]                         |
          |-------------------------------------------------------|
          | XWD[ASCIZ/SYSTEM/],[ASCIZ/PS:<NEW-SYSTEM,PS:<SYSTEM>/]|
          |-------------------------------------------------------|
          | XWD[ASCIZ/EDITOR/],[ASCIZ/SYS:EDIT.EXE/]              |
          +-------------------------------------------------------+
                                                    Page 204


                    SYS-STARTUP-VECTORS

System Startup Transfer Vectors.  This  table,  in  resident
locations  140%-147,  contains  the  startup vectors for the
monitor as well as vectors to enter EDDT.

Defined in:  STG

Referenced by:  STG, POSTLD


                                   Format


           +-------------------------------------------------------+
EVDDT=140  |                 JRST DDTX     (EDDT)                  |
           |-------------------------------------------------------|
           |               JRST SYSDDT     (Reset and go to EDDT)  |
           |-------------------------------------------------------|
EVDDT2=142 |                 JRST DDTX     (Copy of EDDT in case   |
           |                                other clobbered)       |
           |-------------------------------------------------------|
EVDDT2=143 |               JRST SYSLOD     (Initialize disk file   |
           |                                 system)               |
           |-------------------------------------------------------|
           |                        Unused                         |
           |-------------------------------------------------------|
EVRST=145  |               JRST SYSRST     (Restart)               |
           |-------------------------------------------------------|
EVLDGO=146 |               JRST SYSGO      (Reload and start)      |
           |-------------------------------------------------------|
EVGO=147   |               JRST SYSGO1     (Start)                 |
           +-------------------------------------------------------+
                                                    Page 205


                    SYSERR-STORAGE-AREA

SYSERR STORAGE AREA.  This area contains the buffer for  all
SYSERR error blocks which are later written by JOB0 into the
SYSERR.LOG file.  In and out pointers into the  buffer  area
are  maintained for JOB0 as well as pointers to the free and
released SYSERR blocks.

Defined in:  STG, SERCOD

Referenced by:  SYSERR


        +-------------------------------------------------------+
SEBBFR: |                           .                           | / \     / \
        \                           .                           \  |       |
        \                           .                           \  |       |
        |-------------------------------------------------------|          |
        |                      SYSERR HDR                       |SYSERR  SEBBSZ
        |-------------------------------------------------------|BUFFER    |
        |                  Body of Error Code                   |(1 pg.)   |
        |-------------------------------------------------------|          |
        \                           .                           \  |       |
        \                           .                           \ \ /     \ /
        |-------------------------------------------------------|
SEBFRE: |         Ptr to Beginning of Free Contiguous           |
        |                 Area in SYSERR Buffer                 |
        |-------------------------------------------------------|
SEBEFE: |             Ptr to End of Free Contiguous             |
        |                 Area in SYSERR Buffer                 |
        |-------------------------------------------------------|
SEBQIN: |                 JOB 0 Queue %- IN PTR                  | 
        |-------------------------------------------------------|
SEBFCT: |          Free Count%-Contiguous Buffer Space           |
        |-------------------------------------------------------|
SEBRLQ: |            Ptr to Queue of Released Blocks            |
        |-------------------------------------------------------|
SEBJFN: |                JFN for SYSERR.LOG File                |
        |-------------------------------------------------------|
SECHKF: |            Flag to wake Job 0 SYSERR FORK             |
        |-------------------------------------------------------|
SEIETM: |           Time after which failing to OPEN            |
        |               SYSERR LOG File can try again           |
        +-------------------------------------------------------+

Although  the  In-pointer  is  in  this  storage  area   the
corresponding  Out%-pointer in SEBQUO is in a fixed place in
lower core (i.e., location 24), so JOB  0  can  queue  up  a
BUGHLT block after a crash.  One can examine the last SYSERR
block by adding to the right half of the contents of SEBQUO,
SEBDAT plus offset into SYSERR block.
                                                    Page 206


SEBBFR: SYSERR BUFFER BLOCKS

                           SYSERR BLOCK FORMAT
        +-------------------------------------------------------+
        |  |SEBCOD|     SEBSIZ      |          SEBCDR           |*
      0 |  | Code |Blk Size with HDR|   Pointer to Next Block   |
        |-------------------------------------------------------|
        |        |6     SEBSOF    17|           SEBFN           |
      1 |        |Offset to Free    |  JOB 0 Function to Call   |
        |        |  String Space    |                           |
        |-------------------------------------------------------|
SEBHED=2|   SEHCOD    |                           |   SEHLEN    |*
        | Event Code  |                           |Block Length |
        |-------------------------------------------------------|
        |    SEHTAD                                             |
      3 |                     Date and Time                     |
        |-------------------------------------------------------|
        |    SEHUTM                                             |
      4 |                        Uptime                         |
        |-------------------------------------------------------|
        |    SEHSER                                             |
      5 |                      APRID Word                       |
        |                (Processor Serial Number)              |
        |-------------------------------------------------------|
SEBDAT=6|                                                       |
        |                  Body of Error Block                  |
        \                (Dependent on Event Type               \
        \                      See Below)                       \
        |                                                       |
        |                                                       |
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+

         0 2 3 4 5 6              17 18                       35
   Word +-------------------------------------------------------+
     0  |  |SEBCOD|     SEBSIZ      |          SEBCDR           |
        |  | Code |Blk Size with HDR|   Pointer to Next Block   |
        +-------------------------------------------------------+


        Bits       Pointer        Meaning

        3-5        SEBCOD        State Code
                                  SBCFRE=0 on Free List
                                  SBCREL=1 Released
                                  SBCACT=2 Active
        6-17       SEBSIZ        Block Size Including Header
       18-35       SEBCDR        Pointer to Next in List
                                                    Page 207


         0          8                             27          35
  Word  +-------------------------------------------------------+
     2  |   SEHCOD    |                           |   SEHLEN    |
        | Event Code  |                           |Block Length |
        +-------------------------------------------------------+

         Bits        Pointer       Meaning

         0-8         SEHCOD        Event Code (i.e., Block Type)
                                   SEC%RL=101 System Reload
                                   SEC%BG=102 BUGHLT/BUGCHK/BUGINF
                                   SEC%MB=111 Massbus Device Error
                                   SEC%CS=115 Configuration Status 
                                    Change (MTCON)
                                   SEC%FE=130 Front End Error
                                   SEC%11=131 F.E. Reload Entry
                                          (Gives %-11 Reboot Info.)
                                   SEC%HS=133 Halt for KS10
                                   SEC%PT=160 Processor Parity Trap
                                   SEC%PI=161 Processor Parity Intrp.
                                   SEC%P1=162 Parity for Extensible
                                    Controllers
                                   SB%BLK=163 Status Block
                                   SEC%6S=232 DN64 event

        27-35        SEHLEN        Block Length (Including Header)
                                   RL%LEN - System Reload Block Length
                                   BG%LEN - BUGHLT/CHK/INF Block Length
                                   MB%LEN - Massbus Dev. Err Blk Length
                                   CS%SIZ Config Change Blk Length
                                   FE%LEN - F.E. Errors Blk Length
                                   R1%LEN - F.E. Reload Entry Blk Length
                                   HS%LEN KS10 Block Length
                                   PT%LEN - Proc. Parity Trap Blk Length
                                   PI%LEN - Proc. Parity Interrupt Blk Lgh
                                   PI%LN2 Extensible Controllers Blk Lgh
                                   SE%MAS Status Bloc Length
                                                    Page 208


Word 6 to End (Body of Error Block - Dependent on Event Type)

   Event Type 101
     System Reloaded Error Block Data

          +-----------------------------------------------------+
RL%SVN=0  |          ASCII Byte Pointer to System Name          |
          |-----------------------------------------------------|
RL%STD=1  |         Time of System Build (Univ. Format)         |
          |-----------------------------------------------------|
RL%VER=2  |                System Version Number                |
          |-----------------------------------------------------|
RL%SER=3  |                  APR Serial Number                  |
          |-----------------------------------------------------|
RL%OPR=4  |         ASCII Byte Pointer to "Why Reload"          |
          |-----------------------------------------------------|
RL%HLT=5  |          BUGHLT Address (if Auto-Reloaded)          |
          |-----------------------------------------------------|
RL%FLG=6  |                        Flags                        |
          |-----------------------------------------------------| / \
RL%SIZ=7  |                 Monitor Name (Text)                 |  |
          |                                                     | NSVNT=
          |                                                     |  26.
          |                                                     |  |
          |-----------------------------------------------------| \ /
          |                                                     | / \
          |          "Why Reload" Answer String (Text)          |  |
          |                                                     | RLBSZ=
          |                                                     |  16.
          +-----------------------------------------------------+ \ /
RL%LEN=61
                                                    Page 209


   Event type 102

     BUGHLT/CHK/INF  Error Block Data

          +-----------------------------------------------------+
BG%SVN=0  |                 System Name (ASCIZ)                 |
          |-----------------------------------------------------|
BG%SER=1  |                  APR Serial Number                  |
          |-----------------------------------------------------|
BG%VER=2  |                   Monitor Version                   |
          |-----------------------------------------------------|
BG%SDT=3  |                TAD of Monitor Build                 |
          |-----------------------------------------------------|
          |             Type (1,2 or 3) of BUG Call:            |
BG%FLG=4  |             (BG%CHK=1;BG%INF=2;BG%HLT=3)            |
          |-----------------------------------------------------|
BG%ADR=5  |                 Address of HLT/CHK                  |
          |-----------------------------------------------------|
BG%JOB=6  |          FORKX           |         Job Number       |
          |-----------------------------------------------------|
BG%USR=7  |                     User Number                     |
          |-----------------------------------------------------|
BG%PNM=10 |                Program Name (SIXBIT)                |
          |-----------------------------------------------------|
BG%MSG=11 |                   Message (ASCIZ)                   |
          |-----------------------------------------------------| / \
BG%ACS=12 \                         ACS                         \  |
          \                                                     \ 16.
          |-----------------------------------------------------| \ /
BG%PIS=32 |                      PI Status                      |
          |-----------------------------------------------------|
BG%RCT=33 |                   Register Count                    |
          |-----------------------------------------------------|
BG%REG=34 |               Registers (Maximum of 4)              |
          |-----------------------------------------------------|
BG%NAM=40 |                 SIXBIT Name of Check                |
          |-----------------------------------------------------|
BG%DAT=41 |            Time and Date of BUGHLT/BUGCHK           |
          |-----------------------------------------------------|
BG%CNT=42 |          Number of BUG Checks Since Startup         |
          |-----------------------------------------------------|
BG%APS=43 |                APR Flags (CONI APR,)                |
          |-----------------------------------------------------|
BG%PGS=44 |               Pager Flags (CONI PAG,)               |
          |-----------------------------------------------------|
BG%PGD=45 |               Pager Data (DATAI PAG,)               |
          |-----------------------------------------------------|
BG%ERG=46 |                    Error Register                   |
          |-----------------------------------------------------| / \
BG%SIZ=47 |                                                     |  |
          \                     String Area                     \  |
          |                                                     |  |
          |-----------------------------------------------------| 27.
          |                                                     |  |
          \                     String Area                     \  |
                                                    Page 210


          |                                                     |  |
          +-----------------------------------------------------+ \ /
BG%LEN=102
                                                    Page 211



   Event Type 111
     MASS BUS DEV Error Data Block

          +-------------------------------------------------------+
MB%NAM=0  |              Device Name (if available)               |
          |-------------------------------------------------------|
MB%VID=1  |                  Volume ID (SIXBIT)                   |
          |-------------------------------------------------------|
MB%TYP=2  |           Channel,,Device Type - See PHYPAR           |
          |-------------------------------------------------------|
MB%LOC=3  |      Location of Error - Sector or File,,Record       |
          |-------------------------------------------------------|
MB%FES=4  |         Final Error State - Device Dependant          |
          |-------------------------------------------------------|
MB%CNI=5  |                     CONI Initial                      |
          |-------------------------------------------------------|
MB%CIF=6  |                      CONI Final                       |
          |-------------------------------------------------------|
MB%SEK=7  |                    Number of Seeks                    |
          |-------------------------------------------------------|
MB%RED=10 |             Number of Blocks/Frames Read              |
          |-------------------------------------------------------|
MB%WRT=11 |            Number of Blocks/Frames Written            |
          |-------------------------------------------------------|
MB%FIL=12 |                  Filename (Pointer)                   |
          |-------------------------------------------------------|
MB%USR=13 |             User Making Request (Pointer)             |
          |-------------------------------------------------------|
MB%PGM=14 |                    Program Running                    |
          |-------------------------------------------------------|
MB%D1I=15 |                  DATAI PTCR Initial                   |
          |-------------------------------------------------------|
MB%D1F=16 |                   DATAI PTCR Final                    |
          |-------------------------------------------------------|
MB%D2I=17 |                   DATAI PBAR Initial                  |
          |-------------------------------------------------------|
MB%D2F=20 |                   DATAI PBAR Final                    |
          |-------------------------------------------------------|
MB%UDB=21 |         Unit Data Block for JOB 0 BAT Blocks          |
          |-------------------------------------------------------|
MB%IRS=22 |     IORB Status Word, IS.ERR if Hard (See PHYPAR)     |
                                                    Page 212


          |-------------------------------------------------------|
MB%SRE=23 |                   Soft Read Errors                    |
          |-------------------------------------------------------|
MB%SWE=24 |                   Soft Write Errors                   |
          |-------------------------------------------------------|
MB%HRE=25 |                   Hard Read Errors                    |
          |-------------------------------------------------------|
MB%HWE=26 |                   Hard Write Errors                   |
          |-------------------------------------------------------|
MB%PS1=27 |          Position, CYL if Disk, File if Tape          |
          |-------------------------------------------------------|
MB%PS2=30 |                  SURF/SEC or Record                   |
          |-------------------------------------------------------|
MB%CS0=31 |                   Channel Logout 0                    |
          |-------------------------------------------------------|
MB%CS1=32 |                   Channel Logout 1                    |
          |-------------------------------------------------------|
MB%CS2=33 |                   Channel Logout 2                    |
          |-------------------------------------------------------|
MB%CC1=34 |                       First CCW                       |
          |-------------------------------------------------------|
MB%CC2=35 |                      Second CCW                       |
          |-------------------------------------------------------|
MB%MPE=36 |                     Count of MPE                      |
          |-------------------------------------------------------|
MB%NXM=37 |                     Count of NXM                      |
          |-------------------------------------------------------|
MB%FEC=40 |                   Final Error Count                   |
          |-------------------------------------------------------|
MB%CAD=41 |                    Channel Address                    |
          |-------------------------------------------------------|
MB%UAD=42 |                     Unit Address                      |
          |-------------------------------------------------------|
MB%SPE=43 |                Soft Positioning Errors                |
          |-------------------------------------------------------|
MB%HPE=44 |                Hard Positioning Errors                |
          |-------------------------------------------------------|
MB%OVR=45 |                       Overruns                        |
          |-------------------------------------------------------|
MB%ICR=46 |                      Initial TCR                      |
          |-------------------------------------------------------|
MB%REG=47 |       Units Massbus Registers in order with their:    |
          \        Final Contents,, Initial Error Contents        \
          |                                                       |
          +-------------------------------------------------------+
MB%LEN=124
                                                    Page 213


Event Type 115
   Configuration Status Change (logged by MTCON)

          +--------------------------------------------------------+
CS%OPW=0  |                    Operation Code                      |
          |               Codefield is CS%OPR=77B17                |
          |           Codes are:  CS%ADV=0; Attach Device          |
          |                       CS%DDV=1; Detach Device          |
          |--------------------------------------------------------|
CS%HTP=1  |                    Hardware Type                       |
          |        Channel Type        |         Unit Type         |
          |--------------------------------------------------------|
CS%DNM=2  |              Logical Device Name (SIXBIT)              |
          |--------------------------------------------------------|
CS%APS=3  |            Device Address and Serial Number            |
          |--------------------------------------------------------|
CS%RSW=4  |                Offset to Reason String                 |
          +--------------------------------------------------------+
                                                    Page 214



   Event Type 130
     Front End Errors Data Block

          +--------------------------------------------------------+
FE%FJB=0  |                 Fork Number,,Job Number                |
          |--------------------------------------------------------|
FE%DIR=1  |                    Directory Numbers                   |
          |--------------------------------------------------------|
FE%ID=2   |                Front End Software Version              |
          |--------------------------------------------------------|
FE%NAM=3  |                 SIXBIT Name of Program                 |
          |--------------------------------------------------------|
FE%DEV=4  |            Protocol Device Code (1B0=Unknown)          |
          |--------------------------------------------------------|
FE%PTR=5  |             -Length of Data,,Start of Data             |
          |--------------------------------------------------------|
FE%DTE=6  |                       DTE Number                       |
          |--------------------------------------------------------|
FE%BYT=7  |              # of -11 Bytes in the Message             |
          +--------------------------------------------------------+
FE%LEN=10




   Event Type 131
     Front End Reload    ERROR BLOCK DATA
        
          +--------------------------------------------------------+
R1%NUM=0  |                      -11 Number                        |
          |--------------------------------------------------------|
R1%STS=1  |                  Reload Status Bits                    |
          |--------------------------------------------------------|
R1%FNM=2  |                   File Name Pointer                    |
          |--------------------------------------------------------|
R1%ERW=3  |                    -11 Error Word                      |
          |--------------------------------------------------------| / \
          |                                                        |  |
          \                     String Area                        \  20
          |                                                        |  |
          +--------------------------------------------------------+ \ /
R1%LEN=30
                                                    Page 215


     Word     +-----------------------------------------------+
     R1%STS=1 | | | | | | | | | | | |  |  |       |Retry Count|
              +-----------------------------------------------+

                Symbol         Bits        Contents
        
                .R1GTF          0       GTJFN failed for Dump File
                .R1OPF          1       OPENF failed for Dump File
                .R1DPF          2       Dump failed
                .R110E          3       To -10 Error on Dump 
                .R111E          4       To -11 Error on Dump
                .R1ASF          5       ASGPAG failed on Dump
                .R1RLF          6       Reload failed
                .R1PDF          7       -11 didn't Power Down
                .R1PUF          8       -11 didn't Power Up
                .R1RMF          9       ROM did not ACKnowledge
                                         the -10
                .R1BSF          10      -11 Boot Program didn't
                                         make it to the -11
                .R1NRL          11      -11 took more than 1 Min.
                                         to Reload.
                .R1RTC        33-35     Retry Count



                0 1 2               17 18 19 20              35
       Word    +-----------------------------------------------+
       R1%ERW=3|   |Fault Code        |     | Parity Register  |
               +-----------------------------------------------+


                Symbol          Bits          Contents

                               2-17      Fault code as 3 RAD50
                                           characters
                              20-35      Parity Register Valid Only 
                                           if it is Nonzero
                                                    Page 216


Event Type 133
   Halt for KS10


          +--------------------------------------------------------+
HS%COD=0  |             Halt Status Code (Phy. Loc. 0)             |
          |--------------------------------------------------------|
HS%PC=1   |              Program Counter (Phy. Loc. 1)             |
          |--------------------------------------------------------|
HS%PTR=2  |            Halt Status Block Offset Pointer            |
          |--------------------------------------------------------|
CS%PTR=3  |           Clock Stop Blk Offset Pty. (Unused)          !
          !--------------------------------------------------------! / \
HS%HDZ=4  !                                                        !  !
          \                   Halt Status Block                    \ HS%HSZ
          !                                                        !  !
          +--------------------------------------------------------+ \ /


Halt Status Block

          +--------------------------------------------------------+
HS%NUL=0  !                       Magnitude                        !
          !--------------------------------------------------------!
HS%PC=1   !                           PC                           !
          !--------------------------------------------------------!
HS%HR=2   !                   Current Instruction                  !
          !--------------------------------------------------------!
HS%AR=3   !                           AR                           !
          !--------------------------------------------------------!
HS%ARX=4  !                          ARX                           !
          !--------------------------------------------------------!
HS%BR=5   !                     Base Register                      !
          !--------------------------------------------------------!
HS%BRX=6  !                 Base Register Extension                !
          !--------------------------------------------------------!
HS%ONE=7  !                      Constant One                      !
          !--------------------------------------------------------!
HS%EBR=10 !                   Exec Base Register                   !
          !--------------------------------------------------------!
HS%UBR=11 !                   User Base Register                   !
          !--------------------------------------------------------!
HS%MSK=12 !                         Mask                           !
          !--------------------------------------------------------!
HS%FLG=13 !                 Microcode Status Flags                 !
          !--------------------------------------------------------!
HS%PI=14  !                       PI Status                        !
          !--------------------------------------------------------!
HS%X1=15  !             1              !             1             !
          !--------------------------------------------------------!
HS%T0=16  !                           T0                           !
          !--------------------------------------------------------!
HS%T1=17  !                           T1                           !
          !--------------------------------------------------------!
HS%VMA=20 !           VMA Flags                    VMA             !
                                                    Page 217


          !--------------------------------------------------------!
HS%FE=21  !             FE             !             SC            !
          +--------------------------------------------------------+
                                                    Page 218



   Event Type 160
     Processor Parity Trap Error Block Data

          +--------------------------------------------------------+
PT%PFW=0  |                     Page Fail Word                     |
          |--------------------------------------------------------|
PT%BDW=1  |                     Bad Data Word                      |
          |--------------------------------------------------------|
PT%GDW=2  |                     Good Data Word                     |
          |--------------------------------------------------------|
PT%USR=3  |                      User Number                       |
          |--------------------------------------------------------|
PT%JOB=4  |           FORKX           |            JOBN            |
          |--------------------------------------------------------|
PT%PGM=5  |                  Program Name (SIXBIT)                 |
          |--------------------------------------------------------|
PT%PMA=6  |                Physical Memory Address                 |
          |--------------------------------------------------------|
PT%TRY=7  |            Flags          |        Retry Count         |
          +--------------------------------------------------------+
PT%LEN=10


                1 2 3 4                 18                    35
     Word    +-------------------------------------------------+
     PT%TRY=7| | | | | |               | Retry Count           |
             +-------------------------------------------------+


                Symbol         Bits         Contents

                PT%HRO          1         Hard Error
                PT%CCP          2         Cache Failure
                PT%CCH          3         Cache in Use
                PT%ESW          4         Error on Sweep to Core
                              18%-35       Retry Count
                                                    Page 219



   Event Type 161
     Processor Parity Interrupt Error Data Block

          +-------------------------------------------------------+
PI%CNI=0  |                       CONI APR                        |
          |-------------------------------------------------------|
PI%ERA=1  |                          ERA                          |
          |-------------------------------------------------------|
PI%FPC=2  |                          PC                           |
          |-------------------------------------------------------|
PI%SWP=3  |              Number of Errors This Sweep              |
          |-------------------------------------------------------|
PI%AAD=4  |            Logical "AND" of Bad Addresses             |
          |-------------------------------------------------------|
PI%OAD=5  |             Logical "OR" of Bad Addresses             |
          |-------------------------------------------------------|
PI%ADA=6  |               Logical "AND" of Bad Data               |
          |-------------------------------------------------------|
PI%ODA=7  |               Logical "OR" of Bad Data                |
          |-------------------------------------------------------| / \
PI%SBD=10 |               SBUS DIAG Function Data                 |  |
          \                                                       \ 10.
          |-------------------------------------------------------| \ /
PI%ADD=22 |                First 10. Bad Addresses                | / \
          \                                                       \ 10.
          |-------------------------------------------------------| \ /
PI%DAT=34 |               First 10. Bad Data Words                | / \
          \                                                       \ 10.
          |-------------------------------------------------------| \ /
PI%CDA=46 |          Core Ref of First 10. Bad Addresses          | / \
          \                                                       \ 10.
          |-------------------------------------------------------| \ /
PI%FFL=60 |                         Flags                         |
          +-------------------------------------------------------+
PI%LEN=61
                                                    Page 220


                    TT-LINE-DYN-DATA-BLK

Teletype Line Dynamic Data Block.  This block pointed to  by
the  line's entry in TTACTL, holds line specific data and is
built when the line becomes active.  It is deallocated  when
the line becomes inactive.  

There are two shortened forms of the dynamic data block, one
used for a SENDALL type of message and the other for sending
a "ding" when any  character  but  CTRL/C  is  typed  on  an
inactive line.

Defined in:  TTYSRV

Referenced by:  TTYSRV


          +-------------------------------------------------------+
TTFLG1=0  |                        Flags                          |*
          |-------------------------------------------------------|
TTDAT1=1  |                            !  TINTL                   |*
          |  Buffer Info & Term. Type  !    Internal Line Number  |
          |-------------------------------------------------------|
TTSAL1=2  |TSALC                       !  TLTYP                   |
          | Send All Character Count   |  Dev. Disp. Vector Add.  |
          |-------------------------------------------------------|
TTSAL2=3  |TSALP                                                  |
          |              Send All Byte Pointer                    |
          |-------------------------------------------------------|
TTDEV=4   |             Device dependent word                     |
          |          (See Device modules for definitions)         |
          |-------------------------------------------------------|
TTBFRC=5  |0       7|8    11|12   15|16        25|26            35|
          |  TOWRN  | TTNIN | TTNOU |   TIMAX    |  TOMAX         |
          | Wake Up |# of   |# of   |  Max bytes | Max bytes      |
          |  Count  | Input |Output |In Input Buf| In Output Buf  |
          |         | Bufs  | Bufs  |            |                |
          |-------------------------------------------------------|
TTOCT=6   |          Number of Characters in Output Buffer        |
          |-------------------------------------------------------|
TTOOUT=7  |     Pointer for Removing Char from Output Buffer      |
          |-------------------------------------------------------|
TTOIN=10  |     Pointer for Entering Char into Output Buffer      |
          |-------------------------------------------------------|
TTDAT2=11 |              Input Info. & Page Width                 |*
          |-------------------------------------------------------|
TTICT=12  |           Number Characters in Input Buffer           |
          |-------------------------------------------------------|
TTIOUT=13 |      Pointer for Removing Char from Input Buffer      |
          |-------------------------------------------------------|
TTIIN=14  |      Pointer for Entering Char into Input Buffer      |
          |-------------------------------------------------------|
FCMOD1=15 |        Control Character Output Control Words         |
          |-------------------------------------------------------|
          |                                                       |
                                                    Page 221


FCMOD2=16 |     Possible Values for each Char. (2 Bits/Char)      |
          |         CCNONE = 0  Send nothing                      |
          |         CCIND  = 1  Indicate via ^                    |
          |         CCSEND = 2  Send Actual Code                  |
          |         CCSIM  = 3  Simulate Format Action            |
          |-------------------------------------------------------|
TTDPSI=17 |    Bit for Terminal Code Set if Deferred Interrupt    |
          |-------------------------------------------------------|
TTPSI=20  |        Bit for Terminal Code Set if Interrupt         |
          |-------------------------------------------------------|
TTLINK=21 |           Lines linked to (9 bits per line)           |
          |-------------------------------------------------------|
TTLPOS=22 | TPGPS                     | TLNPS                     |
          |  Cur Line Position in Page| Current Charcter Position |
          |                           |        within Line        |
          |-------------------------------------------------------|
TTFLGS=23 |0     !   !10            17|                           |
          |TOFLG |   !TPLEN           |                           |
          |^O was|   ! page length    |                           |
          | typed|   !                |                           |
          |-------------------------------------------------------|
TTFORK=24 | TCJOB                     | TWFRK                     |
          | Controlling Job Number    | Fork Number in Input Wait |
          |                           |        on this Line       |
          |-------------------------------------------------------|
TTFRK1=25 | TTPSFK                    | TTPFK                     |
          |  PSI Fork # for           | Fork which is Top Fork of |
          |  Non-controlling TTY      |  a SCTTY Tree (-1 if None)|
          !-------------------------------------------------------!
TTCHR1=26 !       Wake Up Character Mask (ASCII Codes 0-31.)      !
          !-------------------------------------------------------!
TTCHR2=27 !      Wake Up Character Mask (ASCII Codes 32.-63.)     !
          !-------------------------------------------------------!
TTCHR3=30 !      Wake Up Character Mask (ASCII Codes 64.-95.)     !
          !-------------------------------------------------------!
TTCHR4=31 !      Wake Up Character Mask (ASCII Codes 96.-127.)    !
          !-------------------------------------------------------!
TTFWTH=32 !                           ! TTFCNT                    !
          !       PSI Level Info      !   Byte Count              !
          !-------------------------------------------------------!
TTLINE=33 !                      Line Counter                     !
          !-------------------------------------------------------!
TTLMAX=34 !                   Maximum of TTLINE                   !
          +-------------------------------------------------------+
                                                    Page 222


        0 1 2 3 4 5 6 7 8 9 10 11                    30         35
       +----------------------------------------------------------+
TTFLG1 | | | | | | | | | | |  |  |                  |TTLCK        |
       | | | | | | | | | | |  |  |                  |Cnt. of Locks|
       +----------------------------------------------------------+


        Symbol       Bits        Pointer        Contents

        TT%SAL        0          TTSAL      Sendall being done to
                                             this line
        TT%SHT        1          TTSHT      This is a short block
        TT%MES        2          TTMES      This is a system 
                                             message block
        TT%OTP        3          TTOTP      Output is enroute to 
                                             the line
        TT%FWK        4          TTFWK      Forced wakeup
        TT%SFG        5          TTSFG      CTRL/S was typed
        TT%RFG        6          TTRFG      Repeat last character
                                             (BKJFN)
        TT%WFG        7          TTWFG      Blocked on input
        TT%PRM        8          TTPRM      Don't deallocate 
                                             dynamic data
        TT%BAC        9          TTBAC      Permanent and becoming
                                             active
        TT%NXO       10          TTNXO      Is 0, no page output stop
        TT%BKO       11          TTBKO      Fork blocked for output
                                             event
        TT%LCK      30-35        TTLCK      Count of locks on this 
                                             block
         0   4 5   7 8 9             17 18                        35
        +-----------------------------------------------------------+
TTDAT1  |     |     | |                |  TTINTL                    |
        +-----------------------------------------------------------+


             Bit      Pointer      Contents

             5-7      TTOCN        Count of extra buffers
              8       TTOMX        Extra buffers in use
             9-17     TTTYP        Terminal type
            18-35     TINTL        Internal line number
                                   (index into static data)
                                                    Page 223



         0      6 7 8 9           17 18           26 27          35
        +----------------------------------------------------------+
TTDAT2  |        | | | TYLCH        | TPWID         |              |
        +----------------------------------------------------------+


             Bit      Pointer     Contents

             7-8      TYLMD       Terminal data mode for last
                                   input character
             9-17     TYLCH       Last char removed from input
                                   buffer
            18-26     TPWID       Page width


         0      5 6        11 12        17 18                    35
        +----------------------------------------------------------+
TTFWTH  !        ! TTIPSI    ! TTOPSI     ! TTFCNT                 !
        +----------------------------------------------------------+


             Bit      Pointer     Contents

             6-11     TTIPSI      Input PSI level
            12-17     TTOPSI      Output PSI level
            18-35     TTFCNT      Byte count for wakeup
                                  (0=> disabled for wakeup)
                                                    Page 224


                           TTACTL

Teletype Active Line Table.  This resident table contains  a
pointer to each active line's dynamic data block.

Defined in:  STG

Referenced by:  MEXEC, TTYSRV

Index:  Line Number

                                  Format

        +-------------------------------------------------------+
TTACTL: |       Address of dynamic data block if active         | / \
        |               or -1 if becoming active                |  |
        |                   or 0 if inactive                    |  |
        |-------------------------------------------------------|  |
        |                           .                           |  |
        |                           .                           |   
        |                           .                           | NLINES
        |                           .                           |   
        |                           .                           |  |
        |                           .                           |  |
        |                           .                           |  |
        |                                                       | \ /
        +-------------------------------------------------------+
                                                    Page 225


                           TTBUFS

Teletype Buffers.  This storage area contains the input  and
output  buffers  for  each line (TTY and PTY) on the system.
Input and output pointers to each buffer  are  kept  in  the
line's  dynamic  data block.  These buffers are fixed length
and are assigned on demand.   When  there  is  no  character
activity, the buffers are deassigned.

Defined in:  STG

Referenced by:  TTYSRV


                                Format

        +-----------------------------------------------------+
TTBUFS: |                Pointer to Next Buffer               |
        |-----------------------------------------------------|
        |                                                     |  / \
        |                                                     |   |
        |                                                     |
        |                                                     |Buffer
        |                                                     |   
        |                                                     |  \ /
        |-----------------------------------------------------|
        |                          .                          |
        \                          .                          \
        |-----------------------------------------------------|
        |                 Pointer to Next Buffer              |
        |-----------------------------------------------------|
        |                                                     |  / \
        |                                                     |   |
        |                                                     |
        |                                                     |Buffer
        |                                                     |   
        |                                                     |  \ /
        |-----------------------------------------------------|
        |                          .                          |
        \                          .                          \
        +-----------------------------------------------------+

        Note:  The free buffers are linked and are pointed to by TTFREB.
                                                    Page 226


                           TTCSAD

Terminal Call Special Request Address Table.  This  resident
table  is  used  to hold the dispatch address of a scheduler
routine for a special line request.

Special line requests are made  when  the  DTEQ  routine  is
unable to obtain space for a packet and cannot block to wait
for the space.  (i.e.  process is NOSKED, or request made at
interrupt  or  scheduler  level).  A special line request is
made so that a packet will be queued later by the Scheduler.
(See Table, TTCSTM).

Defined in:  STG

Referenced by:  TTYSRV

Index:  Line Number

                                Format

        +-------------------------------------------------------+
TTCSAD: |       Address of routine for scheduler to call        |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NLINES
        |                           .                           |
        |                                                       |   |
        \                                                       \   |
        |                                                       |  \ /
        +-------------------------------------------------------+
                                                    Page 227


                           TTCSTM

Terminal Call Special Request  Time  Table.   This  resident
table  parallels  the  TTCSAD  table  and holds the time the
Scheduler is to call the special request routine in TTCSAD.

Defined in:  STG

Referenced by:  TTYSRV

Index:  Line Number

                                Format

        +-------------------------------------------------------+
TTCSTM: |     Time for scheduler to call routine in TTCSAD      |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           
        |                           .                           | NLINES
        |                           .                           |
        |                                                       |   |
        |                                                       |   |
        |                                                       |   |
        |                                                       |  \ /
        +-------------------------------------------------------+
                                                    Page 228


                           TTLINV

Terminal Type Line Vector Table.  This  vector  table  gives
the  device  table  addresses  of  the  form, TTXXVT.  These
tables  hold  the  device  specific   vectors   for   device
functions.  (See TTXXVT Table).

Defined in:  TTYSRV

Referenced by:  TTYSRV

Index:  Device Type


                                Format

        +-------------------------------------------------------+
TTLINV: |  IFIW  |  TTFEVT        FE Vector Table               |
        |-------------------------------------------------------|
        |  IFIW  |  TTMCVT*      MCB Vector Table               |
        |-------------------------------------------------------|
        |  IFIW  |  TTPTVT       PTY Vector Table               |
        |-------------------------------------------------------|
        |  IFIW  |  TTDCVT*      DC10 Vector Table              |
        |-------------------------------------------------------|
        |  IFIW  |  TTNTVT     Network Vector Table             |
        |-------------------------------------------------------|
        |  IFIW  |  TTDZVT       DZ11 Vector Table              |
        +-------------------------------------------------------+



                            NOTE

               If a terminal  type  does  not
               exist,    its    corresponding
               vector table address in TTLINV
               will   be  set  equal  to  the
               vector table address,  TTDMVT.
               This table vectors to routines
               which BUGHLT.


       * Are currently not in use.
                                                    Page 229


                           TTSTAT

Teletype Status Table.  This  resident  table  contains  the
terminal characteristic flags

Defined in:  STG

Referenced by:  TTYSRV

Index:  Line Number

                                  Format
        +-------------------------------------------------------+
TTSTAT: |           Terminal Characteristics Flags              |  / \
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |
        |                           .                           | NLINES
        |                           .                           |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+


      0 1 2 3 4 5 6 7 8 10  13 15  17 8 9 20            27 28       35
     +----------------------------------------------------------------+
     | | | | | | | | | |      |      |   |    TSFMC       |   TTFBB   |
     +----------------------------------------------------------------+


Symbol         Bits         Pointer        Contents

TT%FEM          0           TTFEM       Line is remote
TT%NTS          1           TTNTS       Don't send system mesg.
TT%FXO          2           TTFXO       Line needs XON
TT%CON          3           TTCON       Carrier is on
TT%FSP          4           TTFSP       Line needs speed set
TT%FXF          5           TTFXF       Line needs XOF
TT%IGI          6           TTIGI       Ignore input when line
                                        is inactive
TT%AUT          7           TTAUT       Line is auto-speed
TT%XOC          8           TTXOC       Line needs XON/XOFF
                                        character (2020)
TT%FPK          8           TTFPK       Waiting for FE post (KL)
              10-13         TTXCN       Count of XOFFs requested
              15-17         TTYSTY      Line type which yields
                                        the offset into the
                                        TTLINV table
              20-27         TSFMC       Max count for front
                                        end buffer
              28-35         TTFBB       Entry count in Big Buf
                                                    Page 230


                           TTXXVT

Teletype Device Specific Vector Table.  TTXXVT is the vector
table (in generalized format) for data and routine addresses
for device XX.  The offsets given below  can  be  used  when
referencing a device specific vector table.

Teletype service consists of the module  -  TTYSRV  -  which
contains  all  device-independent  code,  and one module for
each  line  type.   The  latter  modules  contain  all   the
device-dependent code for their line type.  

Each device-dependent module, of name TTXXDV, has a transfer
vector table of the name TTXXVT, where XX is unique for each
line type  (i.e.,  XX  =  FE/DZ/DC/MC/NT/PT);   (See  TTLINV
Table).

Defined in:  TTYSRV

Referenced by:  TTYSRV

          +-------------------------------------------------------+
DDLEN=0   |         Length of dynamic data for this type          |
          |-------------------------------------------------------|
TT1LIN=1  |          First line of this type/-1 no lines          |
          |-------------------------------------------------------|
VITBLS=2  |          Initialize tables at system startup          |
          |-------------------------------------------------------|
VACTLN=3  |         Activate lines at startup or restart          |
          |-------------------------------------------------------|
VCLOBF=4  |                  Clear output buffer                  |
          |-------------------------------------------------------|
VSETSP=5  |                    Set line speed                     |
          |-------------------------------------------------------|
VGETSP=6  |                    Read line speed                    |
          |-------------------------------------------------------|
VSETTS=7  |           Set terminal/non-terminal status            |
          |-------------------------------------------------------|
VGETTS=10 |           Read terminal/non-terminal status           |
          |-------------------------------------------------------|
VSTO=11   |                       STO JSYS                        |
          |-------------------------------------------------------|
VSTPAR=12 |                      STPAR JSYS                       |
          |-------------------------------------------------------|
VCKPHY=13 |           CKPHYT - see if physical terminal           |
          |-------------------------------------------------------|
VXON=14   |               Process XON from terminal               |
          |-------------------------------------------------------|
VDETDB=15 |                Deassign TTY Data Base                 |
          |-------------------------------------------------------|
VOPAR=16  |            TCOUT - add parity to character            |
          |-------------------------------------------------------|
VSOUT=17  |                 Start output to line                  |
          |-------------------------------------------------------|
VSXOFF=20 |                 Send XOFF to terminal                 |
                                                    Page 231


          |-------------------------------------------------------|
VSXON=21  |                 Send XON to terminal                  |
          |-------------------------------------------------------|
VTTCS=22  |              TTCH7 - Process TTCS words               |
          |-------------------------------------------------------|
VCON=23   |                   Handle carrier/on                   |
          |-------------------------------------------------------|
VCOFF=24  |                  Handle carrier/off                   |
          |-------------------------------------------------------|
VHNGUP=25 |            Hangup, reactivate remote line             |
          |-------------------------------------------------------|
VXOFF=26  |              Process XOFF from terminal               |
          |-------------------------------------------------------|
RNEWCC=27 |           Handle CTRL/C from inactive line            |
          |-------------------------------------------------------|
VSTOBB=30 |          BIGSTO - Store character in TTBBUF           |
          |-------------------------------------------------------|
VSNDCH=31 |            TTSND - Send character to line             |
          |-------------------------------------------------------|
VDET=32   |                Detach job on this line                |
          |-------------------------------------------------------|
VBBOV=33  |               Handle overflow of TTBBUF               |
          |-------------------------------------------------------|
VGCHBB=34 |             Remove character from TTBBUF              |
          |-------------------------------------------------------|
VTTMSG=35 |                Do TTMSG for one line                  |
          |-------------------------------------------------------|
TSETDS=36 |                Enable/Disable Datasets                |
          |-------------------------------------------------------|
VCKLIN=37 |              TTCH7 after emptying TTBBUF              |
          |-------------------------------------------------------|
VCLIBF=40 |                  Clear input buffer                   |
          |-------------------------------------------------------|
VDOBE=41  |                         DOBE                          |
          |-------------------------------------------------------|
VHNGRY=42 |                       Input GA                        |
          |-------------------------------------------------------|
VSINIV=43 |            Set Initial Values for a line              |
          |-------------------------------------------------------|
VSOBE=44  |                         SOBE                          |
          |-------------------------------------------------------|
VDOBET=45 |             Wakeup if output buffer empty             |
          |-------------------------------------------------------|
VSNDA1=46 |                 Sendall for one line                  |
          |-------------------------------------------------------|
VSNDAL=47 |                 Sendall for all lines                 |
          |-------------------------------------------------------|
VAJWCL=50 |                  Adjust wakeup class                  |
          |-------------------------------------------------------|
VSTPLN=51 |                      Stop Line                        |
          !-------------------------------------------------------!
VSFEXO=52 !      Enable/disable front-end XOFF recognition        !
          !-------------------------------------------------------!
TTVTMX=53 !           Maximum number of vector entries            !
          +-------------------------------------------------------+
                                                    Page 232


                      TTY-STORAGE-AREA

Teletype Storage Area.  This resident area contains hung and
special  line  information,  the Big Buffer, and information
about  the  Big  Buffer.    (See   TT%-LINE%-DYN%-DATA%-BLK,
TTACTL,  TTBUFS, TTCSAD, TTCSTM, TTLINV, TTSPWD, TTSTAT, and
TTXXVT Tables).

Defined in:  STG

Referenced by:  TTYSRV


        +-------------------------------------------------------+
CTYNIT: |      Unit No. on the .FEDLS Device by which the       |
        |                Front End Knows the CTY                |
        |-------------------------------------------------------|
TCOERR: |     TCOUT Sets this if Fails in Scheduler Context     |
        |-------------------------------------------------------|
SALCNT: |             Count of Lines Doing SENDALL              |
        |-------------------------------------------------------|
TTFREC: |                 Count of Free Buffers                 |
        |-------------------------------------------------------|
TTFREB: |                 List of Free Buffers                  |
        |-------------------------------------------------------|
TTBIGI: |              Input Index into Big Buffer              |
        |-------------------------------------------------------|
TTBIGO: |             Output Index into Big Buffer              |
        |-------------------------------------------------------|
TTBIGC: |               Char Count in Big Buffer                |
        |-------------------------------------------------------| / \
TTBBUF: |                      Big Buffer                       |  |
        |                                                       |  |
        \ Storage for all TTY Input Chars. Before Being Placed  \ TTBSIZ
        |  Into Individual Input Line Buffers in TTBUFS Area    | = 200
        |                                                       |  |
        |-------------------------------------------------------| \ /
TTQCNT: |              Count of Special Line Items              |
        |-------------------------------------------------------|
TTCQLN: |            Control of Current Line Number             |
        |-------------------------------------------------------|
TTHNGL: |             Line Being Examined for Hung              |
        |-------------------------------------------------------|
TTHNGT: |      Time at Which Line Will be Defined as Hung       |
        |-------------------------------------------------------|
TTHNGN: |      Last Hung Line      |    No. of Unhangs Done     |
        |-------------------------------------------------------|
LINKF:  |           Linked Output Character if not 0            |
        |-------------------------------------------------------|
IMECHF: |          Immediate Echo Output Char if not 0          |
        |-------------------------------------------------------|
TTCHIC: |               Input Character in TTCHI                |
        |-------------------------------------------------------|
DZCHCT: |               "Clock" for DZ11 PI Check               | 2020 only
        |-------------------------------------------------------| / \
                                                    Page 233


        |                                                       |  |
SNDALL: \             Send All Buffer (^D16 Words)              \ SNDSIZ
        |                                                       | = 41
        +-------------------------------------------------------+ \ /
                                                    Page 234


                            UDB

Unit  Data  Block.   This  block,  one  per  unit,  contains
information about the current activity on the unit.

Defined in:  PHYPAR

Referenced by:  PHYSIO


                                Format

        +-------------------------------------------------------+
UDBSTS=0|       Status and Configuration Information            |
        |-------------------------------------------------------|
UDBMBW=1|        Memory Bandwidth Scheduling Information        |
       .|-------------------------------------------------------|
DBODT  .|         Overdue Timer for Seeks and the Like          |
       .|-------------------------------------------------------|
UDBERR  |              Error Recovery Status Word               |
        |-------------------------------------------------------|
UDBERP  |         Error Reporting Work Area if Nonzero          |
        |-------------------------------------------------------|
UDBDSP  |           Unit Routine Main Entry Dispatch            |
        |-------------------------------------------------------|
UDBCDB  |       Secondary CDB       |        Primary CDB        |
        |-------------------------------------------------------|
UDBADR  |  Secondary Unit Address   |   Primary Unit Address    |
        |-------------------------------------------------------|
UDBAKA  |        Current CDB        |  Current Chain Address    |
        |-------------------------------------------------------|
UDBVID  |                       Volume ID                       |
        |-------------------------------------------------------|
UDBSTR  |    Unit Within Structure    |       Structure #       |
        |-------------------------------------------------------|
UDBKDB  |                Pointer to KDB, if any                 |
        |-------------------------------------------------------|
UDBDSN  |                  Drive Serial Number                  |
        |-------------------------------------------------------|
UDBSEK  |                         Seeks                         |
        |-------------------------------------------------------|
UDBRED  |        Reads (Sectors if Disk, Frames if Tape)        |
        |-------------------------------------------------------|
UDBWRT  |       Writes (Sectors if Disk, Frames if Tape)        |
        !-------------------------------------------------------!
UDBRCT  !                  Actual read count                    !
        !-------------------------------------------------------!
UDBWCT  !                 Actual write count                    !
        |-------------------------------------------------------|
UDBSRE  |                   Soft Read Errors                    |
        |-------------------------------------------------------|
UDBSWE  |                   Soft Write Errors                   |
        |-------------------------------------------------------|
UDBHRE  |                   Hard Read Errors                    |
        |-------------------------------------------------------|
                                                    Page 235


UDBHWE  |                   Hard Write Errors                   |
        |-------------------------------------------------------|
UDBPS1  |      Current Cylinder (if Disk), File (if Tape)       |
        |-------------------------------------------------------|
UDBSP2  |      Current Sector (if Disk), Record (if Tape)       |
        |-------------------------------------------------------|
UDBPWQ  | Position Wait Queue Tail  | Position Wait Queue Head  |
        |-------------------------------------------------------|
UDBTWQ  | Transfer Wait Queue Tail  | Transfer Wait Queue Head  |
        |-------------------------------------------------------|
UDBONR  |        Fork Which Owns This Unit (Maint. Mode)        |
        |-------------------------------------------------------|
UDBERC  |                  Current Retry Count                  |
        |-------------------------------------------------------|
UDBSPE  |                Soft Positioning Error                 |
        |-------------------------------------------------------|
UDBHPE  |                Hard Positioning Error                 |
        |-------------------------------------------------------|
UDBPNM  |             Program Name to Log on Error              |
        |-------------------------------------------------------|
UDBUDR  |         User Directory Number to Log on Error         |
        |-------------------------------------------------------|
UDBSIZ  |            Unit Size (Number of Cylinders)            |
        |-------------------------------------------------------|
UDBFCT  |                  Seek Fairness Count                  |
        |-------------------------------------------------------|
UDBCHB  |             IORB Used by Home Block Check             |
        |-------------------------------------------------------|
UDBFCR  |         Fairness Cnt. for Read Seek Preference        |
        !-------------------------------------------------------!
UDBSLV  !                Slave number if tape                   !
        !-------------------------------------------------------!
UDBCHR  !                Characteristics word                   !
        |-------------------------------------------------------|
UDBDDP  |    Device Dependent Part for MTA or for DSK           |
        \      (See PHYM2 and PHYP4 monitor modules)            \
        \                                                       \
        |                                                       |
        |                                                       |
        +-------------------------------------------------------+
                                                    Page 236



        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 17 18                 31  35
       +--------------------------------------------------------------+
UDBSTS | | | | | | | | | | | | | | | | | |  |                  |      |
       +--------------------------------------------------------------+

Symbol     Bits    Pointer   Content

US.OFS       0     USOFL     Offline or unsafe
US.CHB       1               Check home blocks before any normal
US.POS       2               Positioning in progress
US.ACT       3               Active
US.BAT       4               Bad blocks on this unit
US.BLK       5               Lock bit for this units BAT blocks
US.PGM       6               Dual port switch in (A or B)
                             (RP04,5,6)
US.MAI       7               Unit is in MAINT mode
US.MRQ       8               MAINT mode is requested on this unit
US.BOT       9               Unit is at BOT
US.REW      10               Unit is rewinding
US.WLK      11               Unit is write locked
US.MAL      12               MAINT mode allowed on this unit
US.OIR      13               Operator intervention required.
                             Set at interrupt level, checked
                             at SCHED.
US.OMS      14               Once a minute message to operator.
                             Used in conjunction with US.OIR
US.PRQ      15               Positioning required on this unit
US.TAP      16               Tape type device
US.PSI      17               PSI online/offline/rewind done
                             transition occurred
          31-35    USTYP     Unit Type



                    Type Code for USTYP

Symbol     Code Unit               Symbol      Code Unit

.UTRP4       1  RP04               .UTTM3       12  TM03
.UTRS4       2  RS04               .UTT77       13  TU77
.UTT45       3  TU45               .UTTM7       14  TM78
.UTTM2       4  TM02 (as unit)     .UTT78       15  TU78
.UTRP5       5  RP05               .UTDX2       16  DX20
.UTRP6       6  RP06               .UTT70       17  TU70
.UTRP7       7  RP07               .UTT71       20  TU71
.UTRP8      10  RP08               .UTT72       21  TU72
.UTRM3      11  RM03               .UTT73       22  TU7X
                                                    Page 237


                           UDIORB

UDSKIO IORB Pool.  The free IORBS  are  linked  together  in
UDIORB and this list is pointed to by UIOLST.

Defined in:  STG

Referenced by:  PHYSIO


                                Format


        +-------------------------------------------------------+ / \
UDIORB: \                                                       \  |
        \                                                       \  |
        |                                                       |  |
        |-------------------------------------------------------|  |
        |                                                       |  |
        |                           .                           |  |
        |                           .                           | NUIORB
        |                           .                           |   *
        |                                                       | UIOLEN
        |                                                       |  |
        |-------------------------------------------------------|  |
        \                                                       \  |
        \                                                       \  |
        |                                                       |  |
        +-------------------------------------------------------+ \ /
                                                    Page 238


                            UDS

Unit Dispatch Service Routine Table.  This  table,  one  per
unit  type,  contains  vectored  addresses to unit dependent
functions, and  is  given  in  its  generalized  form.   The
specific  unit dispatch tables are RP4DSP (in PHYP4) for the
disk device, and TM2DSP (in PHYM2) for the  magtape  device.
See  PHYPAR  for definitions of arguments given and returned
on calls to these unit routines.

Defined in:  PHYPAR

Referenced by:  PHYSIO, PHYH2, PHYM2(MTA), PHYP4(DSK), STG


                                  Format

         +-------------------------------------------------------+
UDSINI=0 |                      Initialize                       |
         |-------------------------------------------------------|
UDSSIO=1 |          Start I/O on an IORB, skips if O.K.          |
         |-------------------------------------------------------|
UDSINT=2 |Interrupt Routine (called on interrupts for XFER done) |
         |-------------------------------------------------------|
UDSERR=3 |    Initiate Error Retry (skips if no more retrys)     |
         |-------------------------------------------------------|
UDSHNG=4 | Hung Reset (called from TIMER to reset hung devices)  |
         |-------------------------------------------------------|
UDSCNV=5 |     Convert Unit Linear Address to CYL, SURF, SEC     |
         |-------------------------------------------------------|
UDSLTM=6 |            Return Latency or Best Request             |
         |-------------------------------------------------------|
UDSPOS=7 |      Start Positioning on IORB (skips if O.K.)        |
         |-------------------------------------------------------|
UDSATN=10|                  Attention Interrupt                  |
         |-------------------------------------------------------|
UDSPRQ=11|               Skip if Positioning Required            |
         |-------------------------------------------------------|
UDSSTK=12|               Stack Second Command, Skip if OK        |
         !-------------------------------------------------------!
UDSEXT=13!        Check Legality of Unit, Skip if Existant       !
         +-------------------------------------------------------+
                                                    Page 239


                            UPT

User Process Table.   A  one  page  User  Process  Table  is
associated  with  the  Scheduler  and  with each fork in the
system.  (Those associated with forks  may  be  swapped  out
with  the fork.) However, there is only one UPT known to the
hardware/firmware at any one time.  The UPT known is the one
whose  address  is  pointed  to  by  the  hardware User Base
Register (UBR), which is set-up when a process is chosen  to
run.

UPT contains the dispatch address for process events  (i.e.,
traps) and the user's section map table.

Defined In:  STG

Referenced by:  APRSRV, SCHED


                              Format


         HWPTA: +-------------------------------------+ 
                |        Available to Software        | 
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                \                                     \
                |                                     |
                |                                     |
                \                                     \
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |-------------------------------------| / \
       UPTPPM=  |                                     |  |
       HWPTA+400\              Reserved               \ 20
                |                                     |  |
                |-------------------------------------| \ /
       UPTTPI=  |        Address of LUUO Block        |  
KLLUUO HWPTA+420|                                     |  
                |-------------------------------------|  
       UPTOVI=  |User Arith. Overflow Trap Instruction|  
       HWPTA+421|                                     |  
                |-------------------------------------| 
                |User Stack Overflow Trap Instruction |
                |-------------------------------------|
                |    User Trap 3 Trap Instruction     |
                |-------------------------------------|
       KIMUFL=  |      Flags       |    MUUO OP-AC    | 
                                                    Page 240


FFL    HWPTA+424|                  |                  | 
                |-------------------------------------|
       KIMUPC=  |             MUUO Old PC             | 
FPC    HWPTA+425|                                     | 
                |-------------------------------------|
       KIMUEF=  |              E of MUUO              | 
       HWPTA+426|                                     | 
                |-------------------------------------|
       KIMPCW=  |        MUUO Process Context         | 
UPTPCW HWPTA+427|                                     | 
                |-------------------------------------|
       UPTDSP=  |  Kernel No Trap MUUO New PC (word)  | 
       HWPTA+430|                                     | 
                |-------------------------------------|
                |   Kernel Trap MUUO New PC (word)    |
                |-------------------------------------|
                |Supervisor No Trap MUUO New PC (word)|
                |-------------------------------------|
                | Supervisor Trap MUUO New PC (word)  |
                |-------------------------------------|
                |Concealed No Trap MUUO New PC (word) |
                |-------------------------------------|
                |   Public Trap MUUO New PC (word)    |
                |-------------------------------------|
                |  Public No Trap MUUO New PC (word)  |
                |-------------------------------------|
                |   Public Trap MUUO New PC (word)    |
                |-------------------------------------|
       HWPTA+440|        Reserved for software        |
                |                                     |
                |                                     |
                \                                     \
                |                                     |
                |                                     |
                |-------------------------------------|
       UPTPFW=  |           Page Fail Word            | 
TRAPS0 HWPTA+500|                                     | 
                |-------------------------------------|
       UPTPFL=  |           Page Fail Flags           | 
TRAPFL HWPTA+501|                                     | 
                |-------------------------------------|
       UPTPFO=  |          Page Fail Old PC           | 
TRAPPC HWPTA+502|                                     | 
                |-------------------------------------|
       UPTPFN=  |          Page Fail New PC           | 
       HWPTA+503|                                     | 
                |-------------------------------------|
       HWPTA+504|                                     |
       HWPTA+505|     User Process Execution Time     |
                |-------------------------------------|
       HWPTA+506|                                     |
       HWPTA+507|     User Memory Reference Count     |
                |-------------------------------------|
       HWPTA+510|                                     |
                |                                     |
                                                    Page 241


                \                                     \
       HWPTA+537|                                     |
                |-------------------------------------|
       USECTB=  |              USERSECT               | 
       HWPTA+540|                                     | 
                \                                     \
                |                                     |
       HWPTA+577|             USERSECT37              |
                |-------------------------------------|
       HWPTA+600|                                     |
                |        Available to software        |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
                |                                     |
       HWPTA+777|                                     |
                +-------------------------------------+

    Note:  Approximately 1/4 of the UPT is used for hardware
           cells, leaving the rest available to software.
           The monitor currently uses this area to house the
           first page of the PSB table.  (See PSB table
           description.)
                                                    Page 242


                      USER-PG-MAP-TBL

User Page Map Table.  This 512%-word swappable table,  holds
or  points  to  other  tables  that  hold all of the mapping
information needed by the firmware to  translate  user  mode
virtual  addresses  in  a given section into physical memory
addresses.  It is pointed to  by  an  entry  in  the  forks'
section  table  in  its  User Process Table (UPT).  (See UPT
table description.)

The User Page Map, indexed by a 9 bit  virtual  page  number
(1),  contains  either  the  storage address for the virtual
page if the page exists (immediate pointer) or a pointer  to
where  the  storage address resides in another table (shared
or indirect pointer).  The storage address can be a  memory,
swapping area, or disk page address.

If the Storage address for the virtual  page  referenced  by
the  process  contains  a memory page address (i.e., Storage
Address Bits <12%-17>=0), then the microcode, after  copying
this  translation  information  along with the page's access
bits into the CPU's Hardware Page  Table  (2),  concatenates
this  memory  page  number  with  the index into the page to
compose the complete physical address.

If the storage address for the virtual page referenced  does
not  contain  a  memory  address (i.e., Storage Address Bits
<12%-17> not equal to 0), or the page is non-existant (i.e.,
Null  Pointer word) or the page is being illegally accessed,
the microcode will cause a page trap  to  the  User  Process
Table  (UPT).   The  monitor  is then invoked to perform the
analysis and resolution of the trap condition.

Defined in:  PROLOG

Referenced by:  DIAG, FORK, PAGEM, SCHED
                                                    Page 243



                              FORMAT

UPTA*   +-------------------------------------------------------+  / \
       0|                                                       |   |
        |                   Immediate Pointer                   |   |
        |-------------------------------------------------------|   |
        |0    2| 3         8|       | 12                      35|   |
        | Op   |Access Bits |       |    STGADR                 |   |   
        | Code |            |       |  Storage Address          |   |
        |  1   |            |       |                           |   |
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |                                                       |   |
        |                    Shared Pointer                     |   |
        |-------------------------------------------------------|   |
        |0  2 |3        8|          |18                       35|   |
        | Op  | Access   |          | SPTX                      |   |
        | Code|   Bits   |          |  SPT. index               |
        |  2  |          |          |  (Holds Pg's Stor Adr.)   |Virtual
        |-------------------------------------------------------|  Pg#
        |                          or                           |(0%-777
        |                                                       | octal)
        |                   Indirect Pointer                    |
        |-------------------------------------------------------|   |
        |0  2 |3      8 |9       17 |18                      35 |   |
        | Op  | Access  | IPPGN     | SPTX                      |   |
        | Code|  Bits   |    PN     | SPT index                 |   |
        |  3  |         |           | (Holds Pg Tbl's Stor. Adr)|   |
        |-------------------------------------------------------|   |
        |                          or                           |   |
        |                                                       |   |
        |                     Null Pointer                      |   |
        |-------------------------------------------------------|   |
        |0  2 |3         8|                                     |   |
        |Op   |Access Bits|         0 (Nonexistent Pg)          |   |
        |Code |           |                                     |   |
        |  0  |      0    |                                     |   |
        |-------------------------------------------------------|   |
        |                           .                           |   |
        |                           .                           |   |
        |                           .                           |  \ /
        +-------------------------------------------------------+


    *  UPTA is the monitor's symbol used when it wishes to
       reference the current user's page map table for section 0.
                                                    Page 244



    (1)  A fork's virtual 18%-bit address within a section
         is viewed as an address within a 512%-word page,
         (i.e., virtual page number %- 9 bits), Index into
         page 9%-bits.

    (2)  This 512%-word table is examined first by the 
         microcode for the virtual page translation
         information.  If not there, it then goes to
         the fork's UPTA in memory.


              0 2 3 4 5 6 7 8 9                                    35
             +-------------------------------------------------------+
Page Pointer |   | | | | | | |Dependent on Pointer Type in Bits <0%-2>|
 Word        +-------------------------------------------------------+


       Symbol     Bits                Meaning

       PTRCOD     0%-2                Operation Code for the page
                                      pointer type
                                       IMMCOD = 1  Immediate Pointer
                                       SHRCOD = 2  Share Pointer
                                       INDCOD = 3  Indirect

       PTBUB       3                 Public Bit
       PTWR        4                 Write Access
       PTSOFT      5                 Software Bit
       PTCACH      6                 Cache Bit
       PTCPY       7                 Copy-on-Write (Software Only)
       PTSECM      8                 Section is mapped
       PTLOK       9                 Page is Locked (Immediate
                                      Pointer only)
                                                    Page 245



Pointer Types:

                     0   2 3         8 9  11 2 3 4 5 6 7 18         35
                    +-------------------------------------------------+
  Immediate Pointer |  1  |Access Bits|     | | | | | | |             |
                    +-------------------------------------------------+

        Symbol    Bits      Pointer      Meaning

                  0%-8                   See above

             STORAGE ADDRESS

                 12%-35      STGADR      Storage address
                                        (Interpretation follows)

        NCORTM   12%-17                  Non%-Core Test Mask yielding 
                                          type of storage.
                                        Bits <12%-17>=0 =>
                                               Bits <18%-35>=Memory
                                                Pg Adr.
                                        Bits <12%-17> not equal 0 =>
                                               Bits <18%-35>=Drum/DSK
                                                Adr.
        DSKAB     14                    Storage address is a disk
                                         address

        DSKNB     15                    Temporary bit used with DSKAB
                                         to say that disk address is
                                         newly assigned.

        DRMAB     16                    Storage address is a drum
                                         address

        DRMOB     17                    Used with DRMAB to indicate 
                                         that the swapping area has
                                         overflowed to the disk file
                                         system.  (Since TOPS%-20 
                                         currently uses only the disk
                                         file system for swapping, a
                                         drum storage address will 
                                         always have bits 16 & 17 set.)
                                                    Page 246



        UAABC    17&35                   Temporary bit used by the
                                         monitor's page trap handler
                                         when a copy%-on%-write page
                                         trap has occurred.  If the 
                                         page to be copied is a drum
                                         address, it will be faulted 
                                         in before these bits are used,
                                         avoiding conflict over bit 17.
                                         These bits will signify to a
                                         lower level routine, SWPIN, 
                                         that the page just gotten from
                                         the free list has no backup
                                         address and that it is to get
                                         a copy of another page.



                0   2 3         8 9  11 2 3 4 5 6 7 18          35
               +-------------------------------------------------+
  Null Pointer |  0  |Access Bits|     | | | | | | |             |
               +-------------------------------------------------+

       Symbol       Bits                  Meaning

                    0-8                 These bits will have a value
                                         of 0 for the Null Pointer
                                         case.

       UAAB          17                 Temporary bit used by the
                                         monitor's page trap handler
                                         to say that the page has no
                                         assigned backup address on
                                         disk/drum.
                                                    Page 247




                  0 1 2 3    8               18                    35
                 +---------------------------------------------------+
  Shared Pointer |  2  |Access|             |      SPTX              |
                 |     |  Bits|             |         SPT index      |
                 +---------------------------------------------------+


                  Bits        Pointer           Meaning

                  0-8                          See Above

                 18-35        SPTX             The SPT index is used
                                                to obtain from the SPT,
                                                the page's storage
                                                address.


                    0 1 2 3    8 9          17 18                    35
                   +---------------------------------------------------+
  Indirect Pointer |  3  |Access| IPPGN       | SPTX                   |
                   |     |  Bits|   Page #    |    SPT index           |
                   +---------------------------------------------------+

                  Bits        Pointer           Meaning

                  0-8                          See Above

                  9-17        IPPGN            Page # whose value is used
                                                as an offset into the Page
                                                Table (pointed to by the 
                                                SPT table address plus the
                                                SPT index in bits <18-35>)
                                                to obtain the page's trans-
                                                lation information.

                 18-35        SPTX             The SPT index is used to 
                                                obtain from the SPT the
                                                page table's storage 
                                                address.  The table's
                                                address plus the offset
                                                specified in bits <9-17>
                                                holds the virtual page's
                                                translation information.