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Trailing-Edge - PDP-10 Archives - BB-K911B-SM - sources/syserr.mac
There are 64 other files named syserr.mac in the archive. Click here to see a list.
;<4.MONITOR>SYSERR.MAC.7,  3-Jan-80 08:10:33, EDIT BY R.ACE
;UPDATE COPYRIGHT DATE
;<4.MONITOR>SYSERR.MAC.6, 27-Sep-79 06:58:46, EDIT BY R.ACE
;FIX COMMENT (CHANGE . TO ;)
;<4.MONITOR>SYSERR.MAC.5, 26-Sep-79 15:57:38, EDIT BY HALL
;SYERR - CALL BLTUM1 INSTEAD OF BLTUM FOR EXTENDED ADDRESSING
;<OSMAN.MON>SYSERR.MAC.1, 10-Sep-79 16:06:07, EDIT BY OSMAN
;TCO 4.2412 - Move definition of BUGHLTs, BUGCHKs, and BUGINFs to BUGS.MAC
;<4.MONITOR>SYSERR.MAC.3, 14-Mar-79 10:02:26, EDIT BY KIRSCHEN
;FIX DATA CLOBBERAGE ON LARGE ENTRIES (LARGER THAN SEBBLK)
;<4.MONITOR>SYSERR.MAC.2, 11-Mar-79 13:03:02, EDIT BY KONEN
;UPDATE COPYRIGHT FOR RELEASE 4
;<4.MONITOR>SYSERR.MAC.1, 19-Dec-78 15:41:41, EDIT BY MURPHY
;ADD BLOCK PRIORITY TO SCHED CALL

;THIS SOFTWARE IS FURNISHED UNDER A LICENSE AND MAY ONLY BE USED
;  OR COPIED IN ACCORDANCE WITH THE TERMS OF SUCH LICENSE.
;
;COPYRIGHT (C) 1976,1977,1978,1979,1980 BY DIGITAL EQUIPMENT CORPORATION, MAYNARD, MASS.

	SEARCH PROLOG
	TTITLE SYSERR

;STRUCTURE OF BLOCK
; WORD 0 - HEADER

DEFSTR SEBCDR,,35,18		;PTR TO NEXT IN LIST
DEFSTR SEBSIZ,0,17,12		;SIZE OF THIS BLOCK (INCLUDING HEADER)
DEFSTR SEBCOD,0,5,3		;STATE CODE

;BLOCK STATE CODES

SBCFRE==0			;ON FREE LIST
SBCREL==1			;RELEASED
SBCACT==2			;ACTIVE

; WORD 1 - LOCAL USAGE

DEFSTR SEBFN,1,35,18		;FUNCTION TO CALL IN JOB 0
DEFSTR SEBSOF,1,17,12		;OFFSET TO FREE STRING SPACE

SEBHED==:2			;FIRST REGULAR HEADER WORD

; WORD 2-5 - SYSERR HEADER

DEFSTR SEHCOD,SEBHED,8,9		;EVENT CODE
DEFSTR SEHLEN,SEBHED,35,9		;LENGTH OF BLOCK
DEFSTR SEHTAD,SEBHED+1,35,36		;DATE AND TIME
DEFSTR SEHUTM,SEBHED+2,35,36		;UPTIME
DEFSTR SEHSER,SEBHED+3,35,36		;APRID WORD

SEBDAT==:SEBHED+4			;FIRST DATA WORD
SBSMAX==400			;MAX SIZE, JSYS CALL
SEHWD0==1B17+1B23+4B26		;STANDARD BITS, HEADER WORD
SEBBLK==200			;SIZE OF LOGICAL BLOCK IN SYSERR FILE

;INITIALIZATION

	RESCD

SEBINI::MOVEI T1,SEBBFR		;SETUP FREE AND END-FREE PTRS
	MOVEM T1,SEBFRE
	MOVEM T1,SEBEFE
	MOVEI T1,SEBBSZ		;INIT FREE COUNT
	MOVEM T1,SEBFCT
	MOVEI T1,SEBQOU		;INIT QUEUE
	MOVEM T1,SEBQIN
	SETZM SEBQOU		;INIT OUTPUT POINTER ALSO
	RET
;ALLOCATE SYSERR BLOCK
; T1/ SIZE (NOT INCLUDING HEADER AND LOCAL DATA)
; T2/ OFFSET TO STRING STORAGE (I.E. SIZE OF HEADER AND DATA)
;	CALL ALCSEB
; RETURN +1: FAILURE, NO BUFFER SPACE AVAILABLE
; RETURN +2: SUCCESS, T1/ PTR TO BLOCK

;THIS ROUTINE MAY BE CALLED AT ANY PI LEVEL.  IT TURNS THE PI SYSTEM
;OFF WHILE MANIPULATING LISTS, BUT WAS DESIGNED TO MINIMIZE THE
;DURATION OF PI DISABLING.  THE FIRST TWO WORDS OF THE RETURNED BLOCK
;ARE USED FOR LOCAL PURPOSES AS DEFINED ABOVE.  THE ACTUAL SYSERR
;DATA BEGINS IN THE THIRD WORD AND CONSTITUTES THE REMAINDER OF THE BLOCK.

ALCSEB::CONSZ PI,PIPION		;PI NOW ON?
	SKIPA T3,[PION]		;YES
	MOVX T3,<JFCL>		;NO, REMEMBER STATE
	ADDI T1,SEBDAT		;INCLUDE SPACE FOR HEADER
	ASUBR <ARG1,ARG2,PIF>
ALCSE1:	MOVN T2,T1		;GET NEGATIVE OF DESIRED SIZE
	MOVEI T3,SEBBFR		;SETUP IN CASE WRAPAROUND
	MOVNI T4,SEBBFR+SEBBSZ	; "
	PIOFF			;INTO THE TUNNEL....
	CAMLE T1,SEBFCT		;ENOUGH SPACE FOR REQUEST?
	JRST ALCSEX		;DEFINITELY NOT
	ADD T1,SEBFRE		;COMPUTE END OF BLOCK
	CAIL T1,SEBBFR+SEBBSZ	;ENOUGH SPACE BEFORE END?
	JRST ALCSE2		;NO
	ADDM T2,SEBFCT		;UPDATE FREE COUNT
	EXCH T1,SEBFRE		;UPDATE FREE POINTER
	XCT PIF			;RESTORE PI
ALCSE3:	HRLZ T2,T1		;CLEAR BLOCK--SOURCE
	HRRZS T1			;CLEAR SECTION NUMBER
	HRRI T2,1(T1)
	HRRZ T3,T1
	ADD T3,ARG1		;SIZE
	SETZM 0(T1)
	BLT T2,-1(T3)
	MOVE T2,ARG1		;GET SIZE
	STOR T2,SEBSIZ,(T1)	;PUT IN BLOCK
	MOVX T2,SBCACT		;SET CODE TO ACTIVE
	STOR T2,SEBCOD,(T1)
	MOVE T2,ARG2		;INIT STRING STG PTR
	ADDI T2,SEBDAT		;MAKE RELATIVE TO BLOCK ORIGIN
	STOR T2,SEBSOF,(T1)
	RETSKP			;DONE
;HERE IF SPACE TO END OF BUFFER INSUFFICIENT FOR CURRENT REQUEST

ALCSE2:	ADD T4,SEBFRE		;COMPUTE (NEG) SPACE TO END OF BUFFER
	ADDM T4,SEBFCT		;ASSIGN IT
	EXCH T3,SEBFRE		;WRAPAROUND FREE POINTER
	XCT PIF			;RESTORE PI
	MOVN T4,T4		;GET POS COUNT
	CAMN T4,ARG1		;EQUAL TO REQUEST?
	JRST [	MOVE T1,T3	;YES, CAN USE BLOCK JUST ASSIGNED
		JRST ALCSE3]
	STOR T4,SEBSIZ,(T3)	;SET SIZE OF BLOCK
	PIOFF
	EXCH T3,SEBRLQ		;PUT BLOCK ON LIST TO BE RELEASED
	STOR T3,SEBCDR,@SEBRLQ
	XCT PIF			;RESTORE PI
	AOS SECHKF		;WAKEUP JOB 0 FOR RELEASE
	MOVE T1,ARG1		;GET ORIG REQUEST.  HAVE DONE WRAPAROUND
	JRST ALCSE1		; OF BUFFER, GO TRY REQUEST AGAIN

;HERE IF INSUFFICIENT SPACE IN BUFFER FOR REQUESTED BLOCK

ALCSEX:	XCT PIF			;RESTORE PI
	RET
;RELEASE SYSERR BLOCK
; T1/ PTR TO BLOCK
;	CALL RELSEB
; RETURN +1 ALWAYS, BLOCK RELEASED

	SWAPCD

RELSEB::CAME T1,SEBEFE		;RELEASING CONTIGUOUS BLOCK?
	JRST [	MOVX T2,SBCREL	;NO, SET CODE TO RELEASED
		STOR T2,SEBCOD,(T1) ;LEAVE BLOCK TO BE PICKED UP LATER
		RET]
RELSE1:	MOVX T2,SBCFRE		;SET CODE TO FREE
	STOR T2,SEBCOD,(T1)
	LOAD T2,SEBSIZ,(T1)	;GET SIZE
	ADD T1,T2		;COMPUTE END ADR OF BLOCK
	CAIN T1,SEBBFR+SEBBSZ	;END OF BUFFER?
	MOVEI T1,SEBBFR		;YES, WRAPAROUND
	MOVEM T1,SEBEFE		;UPDATE END-FREE POINTER
	ADDM T2,SEBFCT		;UPDATE FREE COUNT
	LOAD T2,SEBCOD,(T1)	;CHECK CODE OF NEXT BLOCK
	CAME T1,SEBFRE
	CAIE T2,SBCREL		;RELEASED?
	RET			;NO, DONE
	JRST RELSE1		;YES, APPEND IT TO FREE LIST

;JOB 0 FUNCTION TO RELEASE BLOCKS ON RELEASE QUEUE

SEBRBB:	SKIPN SEBRLQ		;ANYTHING ON QUEUE?
	RET			;NO
	PIOFF
	LOAD T1,SEBCDR,@SEBRLQ	;GET NEXT ITEM
	EXCH T1,SEBRLQ
	PION
	CALL RELSEB		;RELEASE IT
	JRST SEBRBB		;DO ALL ITEMS
;QUEUE SYSERR BLOCK FOR JOB 0.
; T1/ PTR TO BLOCK
;	CALL QUESEB
; RETURN +1 ALWAYS, BLOCK QUEUED
;MAY BE CALLED AT ANY PI LEVEL.

	RESCD

QUESEB::CONI PI,T2		;SAVE PI STATE
	SETZRO SEBCDR,(T1)	;MARK NEW END OF LIST
	PIOFF
	STOR T1,SEBCDR,@SEBQIN	;APPEND TO END OF QUEUE
	MOVEM T1,SEBQIN		;UPDATE END PTR
	TXNE T2,PIPION		;PI WAS ON?
	PION			;YES, RESTORE IT
	AOS SECHKF		;FIRE UP JOB 0
	RET

;UNQUEUE NEXT ITEM FROM SYSERR JOB 0 QUEUE
;	CALL UNQSEB
; RETURN +1: NOTHING LEFT ON QUEUE
; RETURN +2: SUCCESS, T1/ PTR TO BLOCK

	SWAPCD

UNQSEB::SKIPN T1,SEBQOU		;ANYTHING IN QUEUE?
	RET			;NO
	PIOFF
	LOAD T1,SEBCDR,(T1)	;YES, GET CDR
	JUMPN T1,.+3		;QUEUE BECOMING EMPTY?
	MOVEI T2,SEBQOU		;YES, FIX IN PTR
	MOVEM T2,SEBQIN
	EXCH T1,SEBQOU
	PION
	RETSKP
;COPY DATA AND STRINGS INTO SYSERR BLOCK
; T1/ POINTER TO BLOCK
; T2/ -N,,ADR	- PTR TO LIST OF ITEMS
;	CALL SEBCPY
; RETURN +1: FAILURE (NO CASES AT PRESENT)
; RETURN +2: SUCCESS
;THIS ROUTINE MOVES DATA INTO THE SYSERR BLOCK AND ALLOCATES STRING
;STORAGE AS NEEDED.

	RESCD

SEBCPY::SAVEQ
	DMOVEM T1,Q1		;KEEP BLK PTR, LIST PTR IN Q1, Q2
SEBCP1:	LOAD T4,SEBOFS,(Q2)	;GET OFFSET FOR NEXT ITEM
	ADDI T4,SEBDAT(Q1)	;MAKE POINTER TO ACTUAL WORD
	MOVEI T3,@0(Q2)		;GET POINTER TO DATA
	LOAD T1,SEBTYP,(Q2)	;GET DATA TYPE
	CAIGE T1,NSBTTB		;LEGAL?
	JRST @SBTTB(T1)		;DISPATCH
	LOAD T4,SEHCOD,(Q1)	;GET EVENT CODE INTO T4
	BUG(SEBUDT,<<T1,D>,<T4,D>>)
SEBCP9:	AOBJN Q2,SEBCP1		;LOOP FOR ALL ITEMS
	RETSKP			;DONE

;POINTER TYPE DISPATCH TABLE.  POINTER CODES CHECKED HERE ALTHOUGH
;DEFINED IN PROLOG.  CONFLICTING DEFINITION WILL PRODUCE
;MULDEF GLOBAL DURING LINK

SBTTB:	PHASE 0
SBTWD::	IFIW!SEBCP2		;FULL WORD
SBTSTR::IFIW!SEBCP3		;STRING (ASCIZ)
SBTEVC::IFIW!SEBCP4		;EVENT CODE
SBTFNA::IFIW!SEBCP5		;FUNCTION ADDRESS
	DEPHASE
NSBTTB==.-SBTTB

;DISPATCH ON POINTER TYPE IS EXECUTED WITH:
; T3/ POINTER TO DATA ITEM
; T4/ POINTER TO WORD IN SYSERR BLOCK

;FULL WORD

SEBCP2:	MOVE T1,0(T3)		;GET DATA
	MOVEM T1,0(T4)		;PUT INTO BLOCK
	JRST SEBCP9		;DONE
;STRING - ALLOCATE STORAGE AT END OF BLOCK, COPY STRING, SET POINTER

SEBCP3:	HRLI T3,(POINT 7,0)	;MAKE BYTE PTR TO SOURCE STRING
	LOAD T2,SEBSOF,(Q1)	;GET OFFSET TO FREE STRING STG
	MOVEI T1,-SEBDAT(T2)	;MAKE PTR RELATIVE TO DATA AREA
	MOVEM T1,0(T4)		;PUT PTR IN BLOCK
	LOAD T4,SEBSIZ,(Q1)	;GET SIZE OF BLOCK
	SUB T4,T2		;COMPUTE FREE SPACE LEFT
	JUMPLE T4,SEBCP7	;JUMP IF NONE
	IMULI T4,5		;COMPUTE NUMBER BYTES LEFT
	ADDI T2,0(Q1)		;MAKE PTR TO DESTINATION STRING
	HRLI T2,(POINT 7,0)	;MAKE BYTE PTR
SEBCP8:	SOJL T4,[SETZ T1,	;SPACE EXHAUSTED, TERMINATE
		DPB T1,T2	;STRING AS IS
		JRST SEBCP7]
	ILDB T1,T3		;COPY A BYTE
	IDPB T1,T2
	JUMPN T1,SEBCP8		;COPY UNTIL NULL TERMINATOR
	MOVEI T2,1(T2)		;DONE, GET ADR OF NEXT FREE WORD
	SUBI T2,0(Q1)		;COMPUTE PTR TO FREE SPACE
	STOR T2,SEBSOF,(Q1)	;UPDATE BLOCK
	JRST SEBCP9		;DONE

;HERE IF INSUFFICIENT STORAGE FOR STRING

SEBCP7:	BUG(SEBISS)
	LOAD T1,SEBSIZ,(Q1)	;UPDATE FREE STRING PTR
	STOR T1,SEBSOF,(Q1)
	JRST SEBCP9

;EVENT CODE

SEBCP4:	STOR T3,SEHCOD,(Q1)	;CODE IS IMMEDIATE
	JRST SEBCP9

;FUNCTION ADDRESS

SEBCP5:	STOR T3,SEBFN,(Q1)	;STORE IMMEDIATE VALUE
	JRST SEBCP9
;JSYS TO LOG INFORMATION IN SYSERR FILE
; T1/ ADDRESS OF BLOCK
; T2/ SIZE OF BLOCK
;	SYERR
; RETURN +1: SUCCESS.  ITRAP IF FAILURE

	SWAPCD

.SYERR::MCENT
	MOVE T1,CAPENB
	TXNN T1,SC%WHL+SC%OPR+SC%MNT ;CAPS?
	ITERR CAPX1
	UMOVE T1,T2		;GET SIZE
	CAIL T1,1		;REASONABLE?
	CAIL T1,SBSMAX
	ITERR SYEX1		;NO
	MOVE T2,T1		;ALLOW NO EXTRA STRING STG
	NOSKED
	CALL ALCSEB		;ALLOCATE A BLOCK
	 ITERR (SYEX2,<OKSKED>)	;NO ROOM
	OKSKED
	PUSH P,T1		;SAVE BLOCK POINTER
	MOVEI T3,SEBHED(T1)	;SETUP BLT PTR - DEST
	UMOVE T1,T2		;GET COUNT
	UMOVE T2,T1		;USER BUFFER ADDRESS
	CALL BLTUM1		;DO BLT FROM USER TO MONITOR
	POP P,T1		;RESTORE BLOCK POINTER
	CALL QUESEB		;QUEUE BLOCK
	MRETNG			;RETURN GOOD
;START SYSERR LOGGING FORK - CALLED FROM JOB 0 ONLY

SERINI::MOVX T1,1B1		;XMIT CAPABILITIES
	CFORK
	 BUG(SERFRK)
	MOVEI T2,SEBRUN		;START PC
	MSFRK			;START IN EXEC MODE
	RET

;MAIN SYSERR LOGGING LOOP.
;JOB 0 FORK STARTED HERE AT SYSTEM STARTUP

SEBRUN::MOVX T1,UMODF		;INIT CONTEXT
	MOVEM T1,FFL
	SETZM FPC
	MCENTR
	CALL SEBOFI		;OPEN SYSERR FILE
	 JRST SEBLUP		;CAN'T - KEEP GOING ANYHOW
	MOVE T1,SEBJFN		;CLOSE IT
	CLOSF
	 JFCL
SEBLUP:	MOVEI T1,SEBTST
	MOVSI T2,FHV1		;LOW PRIORITY
	HDISMS
	SETZM SECHKF		;CLEAR FLAG
	CALL SEBRBB		;PROCESS RELEASE QUEUE
	CALL SEBCHK		;PROCESS QUEUE
	JRST SEBLUP

	RESCD

SEBTST:	SKIPN SECHKF
	JRST 0(4)
	JRST 1(4)

	SWAPCD
;INITIALIZATION - OPEN SYSERR LOG FILE

SEBOFI:	TRVAR <NEWFLG>
	SETZM NEWFLG		;NO NEW SYSERR FILE YET
	MOVE T1,TODCLK
	CAMGE T1,SEIETM		;AT LEAST 1 MINUTE AFTER PREVIOUS FAILURE?
	RET			;NO, RETURN FAILURE
	MOVX T1,GJ%OLD+GJ%PHY+GJ%SHT
	HRROI T2,SEFLNM
	GTJFN			;TRY FOR EXISTING SYSERR FILE
	 JRST SEBOF1		;THAT VERSION FAILED, TRY NEXT ONE
SEBOF3:	MOVEM T1,SEBJFN		;SAVE JFN
	MOVX T2,OF%RD+OF%WR
	OPENF
	 JRST [	MOVE T1,SEBJFN	;BAD VERSION, TRY NEXT ONE
		RLJFN
		 JFCL
		SKIPE NEWFLG	;WERE TRYING FOR NEW FILE?
		JRST SEBOF2	;YES, DISASTER
		JRST SEBOF1]	;NO, TRY FOR NEW VERSION
	MOVE T1,SEBJFN
	HRLI T1,.FBBYV
	MOVX T2,<MASKB 6,11>	;SPECIFY BYTE SIZE FIELD
	MOVX T3,^D36B11		;SET IT TO 36-BIT BYTES
	CHFDB
	RETSKP

SEBOF1:	MOVX T1,GJ%FOU+GJ%PHY+GJ%SHT
	HRROI T2,SEFLNM
	GTJFN			;TRY FOR NEW VERSION
	 JRST SEBOF2		;TOTAL LOSS
	SETOM NEWFLG		;NOTE NEW FILE STARTED
	JRST SEBOF3

SEBOF2:	BUG(SERGOF)
	MOVX T1,^D60000		;COMPUTE 1 MINUTE FROM NOW
	ADD T1,TODCLK
	MOVEM T1,SEIETM		;WON'T TRY AGAIN UNTIL THEN
	RET			;RETURN FAILURE

SEFLNM:	ASCIZ /<SYSTEM>ERROR.SYS/
;ROUTINE TO COPY SYSERR BLOCKS FROM BUFFER INTO FILE
;	CALL SEBCHK
;CALLED UNDER JOB 0 ONLY.

SEBCHK::TRVAR <SEBOAD,SEBFBN,SEBWDN,SEBFOF,SEBOLN,SEBOID>
	SETZM SEBFOF		;NOTE SYSERR FILE NOT OPEN
SEBCH0:	CALL UNQSEB		;UNQUEUE NEXT BLOCK
	 JRST [	SKIPN SEBFOF	;NONE, SYSERR FILE OPEN?
		RET		;NO, DONE.
		MOVE T1,SEBJFN	;YES, CLOSE IT
		CLOSF
		 JFCL
		RET]
	MOVEM T1,Q1		;Q1 HOLDS PTR TO BLOCK
	SKIPN SEBFOF		;SYSERR FILE OPEN?
	CALL SEBOFI		;NO, OPEN IT
	 SKIPA			;FAILED, FILE NOT OPEN
	SETOM SEBFOF		;NOTE FILE NOW OPEN
	LOAD T4,SEBFN,(Q1)	;GET FUNCTION
	MOVE T1,Q1		;SETUP BLOCK ADR FOR CALL
	SKIPE T4		;ONE GIVEN?
	CALL 0(T4)		;YES, CALL IT
	SKIPN SEBFOF		;FILE OPEN?
	JRST SEBCHX		;NO, FORGET REST OF PROCEDURE
	LOAD Q2,SEBSOF,(Q1)	;GET FINAL LENGTH OF BLOCK
	MOVEI T1,-SEBDAT(Q2)	;LENGTH OF BODY ONLY
	STOR T1,SEHLEN,(Q1)	;SET LENGTH
	SUBI Q2,SEBHED		;LESS LOCAL HEADER
	MOVEM Q2,SEBOLN		;SAVE ORIGINAL LENGTH
	MOVX T1,SEHWD0		;GET HEADER BOILERPLATE
	IORM T1,SEBHED(Q1)	;PUT IN HEADER
	CALL LGTAD		;GET DATE AND TIME (FRACTION)
	STOR T1,SEHTAD,(Q1)
	SUB T1,TADIDT		;COMPUTE UPTIME IN UNIVERSAL UNITS
	STOR T1,SEHUTM,(Q1)
	CALL GAPRID		;GET APRID WORD
	STOR T1,SEHSER,(Q1)
	MOVEI T1,SEBHED(Q1)	;SETUP PTR TO FIRST WORD TO BE MOVED
	MOVEM T1,SEBOAD
	MOVE T1,SEBJFN		;THE SYSERR FILE JFN
	MOVE T2,[1,,.FBSIZ]	;READ CURRENT EOF POINTER
	MOVEI T3,SEBFBN		;INTO SEBFBN
	GTFDB
SEBCH1:	MOVE T1,SEBFBN		;COMPUTE PAGE NUMBER AND WORD FOR APPEND
	IDIVI T1,PGSIZ
	MOVEM T1,SEBFBN		;SAVE PAGE NUMBER
	MOVEM T2,SEBWDN		;SAVE WORD NUMBER
	HRL T1,SEBJFN		;CONSTRUCT PAGE IDENT
	MOVEM T1,SEBOID		;SAVE IT
	CALL JFNOFN
	 JRST SEBCHX		;LOSE - DISCARD DATA
	MOVE T2,[PTRW+FPG2A]
	CALL SETMPG		;MAP FILE PAGE
	MOVE T1,SEBWDN		;GET WORD NUMBER
	IDIVI T1,SEBBLK		;GET WORD WITHIN SYSERR BLOCK
	JUMPG T2,SEBCH2		;FIRST WORD?
	MOVE T3,SEBWDN		;YES, STORE POINTER
	MOVEI T4,1		;POINT TO THIS ENTRY UNLESS
	CAME Q2,SEBOLN		;NOT AT BEGINNING
	ADD T4,Q2		;POINT TO END OF THIS ENTRY
	CAIL T4,SEBBLK		;WILL THIS ENTRY USE THE ENTIRE BLOCK ?
	MOVEI T4,-1		;YES, MARK NO NEW ENTRY STARTS IN THIS BLOCK
	TLO T4,775000		;SET HIG ORDER BITS TO INDICATE START OF BLOCK
	MOVEM T4,FPG2A(T3)
	AOS SEBWDN		;NOTE ONE ADDITIONAL WORD USED IN FILE
	MOVEI T2,1		;ACCOUNT FOR POINTER WORD
	; ..
;SEBCHK...

SEBCH2:	MOVN T2,T2		;COMPUTE SPACE LEFT IN CURRENT SYSERR BLK
	ADDI T2,SEBBLK
	MOVE T1,Q2		;GET SPACE NEEDED FOR OUTPUT BLOCK
	CAMLE T1,T2		;LESS THAN SPACE AVAILABLE?
	MOVE T1,T2		;NO, USE ALL SPACE AVAILABLE
	SUB Q2,T1		;UPDATE REMAINING OUTPUT COUNT
	HRLZ T2,SEBOAD		;GET POINTER TO OUTPUT DATA
	ADDM T1,SEBOAD		;UPDATE FOR WORDS BEING DONE
	HRR T2,SEBWDN		;MAKE BLT PTR
	ADDM T1,SEBWDN		;UPDATE FILE PTR FOR WORDS BEING DONE
	HRRI T2,FPG2A(T2)	;MAKE PTR TO FILE WINDOW PAGE
	ADDI T1,0(T2)		;COMPUTE ADR OF END
	BLT T2,-1(T1)		;COPY DATA
	SETZ T1,		;UNMAP FILE WINDOW
	MOVEI T2,FPG2A
	CALL SETMPG
	MOVE T1,SEBOID		;GET IDENT OF FILE PAGE
	MOVEI T2,1		;UPDATE IT TO DISK
	UFPGS
	 JFCL
	MOVE T3,SEBFBN		;COMPUTE NEW EOF PTR
	IMULI T3,PGSIZ
	ADD T3,SEBWDN
	MOVEM T3,SEBFBN
	JUMPG Q2,SEBCH1		;LOOP IF MORE IN OUTPUT BLOCK
	MOVE T3,SEBFBN		;GET FINAL EOF PTR
	SETO T2,		;PUT IT IN FDB
	MOVE T1,SEBJFN
	HRLI T1,.FBSIZ
	CHFDB
SEBCHX:	MOVE T1,Q1		;BLOCK DONE, RELEASE IT
	CALL RELSEB
	JRST SEBCH0		;TRY FOR ANOTHER BLOCK

	TNXEND
	END