Trailing-Edge
-
PDP-10 Archives
-
decuslib10-01
-
43,50147/resdec.doc
There are no other files named resdec.doc in the archive.
PROGRAM RESDEC
--------------
RECONSTRUCTION OF A DECTAPE'S DIRECTORY
---------------------------------------
AUTHOR: C.B. ECKHARDT
ADDRESS: AERONAUTICAL RESEARCH LABS
FISHERMENS BEND
VICTORIA
AUSTRALIA
############
# USE: #
############
RESDEC IS A PROGRAM DESIGNED TO BE USED MAINLY WHEN A DECTAPE'S
DIRECTORY GETS OVERWRITTEN WITH GARBAGE, OR ZEROED UNINTENTIONALLY.
IT MAY ALSO BE OF USE IF SOME BLOCKS GET OVERWRITTEN, SINCE CERTAIN
PARTIAL FILES ARE RECOVERABLE.
###################
# WHAT IT DOES: #
###################
RESDEC RECONSTRUCTS A DECTAPE'S DIRECTORY BY READING THE LINK
WORDS IN ALL DATA BLOCKS. FOR EACH COMPLETE FILE FOUND A NAME
(FILE1,FILE2,...FILE22) IS ENTERED IN THE DIRECTORY BLOCK, AND THE
REQUISITE DIRECTORY BLOCK "SLOTS" UPDATED AS REQUIRED.
IF MORE THAN 22 COMPLETE FILES ARE FOUND, THE EXTRA ONES ARE
OUTPUT ON TO DSK WITH THE FILE-NAMES(FILEX1,FILEX2,...).
RESDEC ALSO ENABLES THE USER TO RECLAIM PARTIAL FILES OF THE
FOLLOWING TWO TYPES:
(1) THE FIRST N LINKED BLOCKS OF A FILE ARE FOUND, AND
(2) THE LAST N LINKED BLOCKS OF A FILE ARE FOUND.
IN THE INITIAL RUN OF RESDEC (SEE SAMPLE TTY OUTPUT) THE USER
IS MERELY INFORMED OF THE EXISTENCE OF ANY PARTIAL FILES. (ENTRIES
UNDER THE HEADING "NO. OF BLOKS" GIVE THE NO. OF BLOCKS (IN OCTAL)
ON DECTAPE.)
BY USING THE REENTER COMMAND THE USER CAN RECLAIM ANY OF THE
PARTIAL FILES REQUIRED. IN THE ORDER THEY ARE REQUESTED THEY WILL
BE OUTPUT ON TO DSK WITH THE FILE-NAMES BITSF1,BITSF2,...BITSF9.
####################
# HOW TO USE IT: #
####################
[1] MOUNT THE DECTAPE WRITE-ENABLED AND ASSIGN IT.
RUN RESDEC.SAV.
[2] WHEN THE PROGRAM HAS EXITED, A LISTING OF THE DECTAPE'S
DIRECTORY SHOULD BE OBTAINED . THE NO. OF BLOCKS LISTED
FOR THE FILE-NAMES, WHEN COMPARED TO AN OLD DIRECTORY LIST-
ING, SHOULD SPEED UP THE IDENTIFICATION (I.E. RENAMING) OF
FILE1,FILE2,ETC. CONSIDERABLY (AS COMPARED TO TYPING OUT
THE FIRST FEW LINES OF EACH OF FILE1,FILE2,ETC.).
[3] IN ORDER TO ACCESS ANY OF THE PARTIAL FILES FOUND,
FOLLOW THE PROCEDURE ILLUSTRATED IN THE SAMPLE TTY OUTPUT.
AFTER EACH REQUEST FOR A PARTIAL FILE THE MESSAGE:
1ST. BLOK# =
INDICATES THAT THE FILE HAS BEEN OUTPUT ON TO DSK AS A FILE
CALLED BITSF1,BITSF2,...BITSF9.
TO EXIT TYPE ^C.
IF THE USER WISHES TO WRITE OUT MORE THAN 9 PARTIAL
FILES, HE MUST RENAME OR DELETE AS MANY OF THE FILES
BITSF1,BITSF2,ETC. AS THOSE HE REQUIRES IN EXCESS OF 9.
THIS IS BECAUSE FOR EACH REQUEST IN A PARTICULAR .REE, A
LOOKUP IS DONE FOR THE FILE-NAMES BITSF1,BITSF2,ETC. ON
DSK. IF ALL 9 FILE-NAMES ARE ON DSK THE ERROR MESSAGE
NOTE-3
WILL BE TYPED OUT.
[4] NO PROBLEMS SHOULD BE ENCOUNTERED IN RUNNING RESDEC
ON OTHER INSTALLATIONS. RESDEC.MAC IS ASSEMBLED AND
LOADED IN THE NORMAL FASHION, RESULTING IN A NON-REENTRANT
SAV VERSION. RESDEC IS A NON-SHARABLE PROGRAM.
#######################
# SAMPLE TTY OUTPUT #
#######################
.R PIP
*DSK:/X_DTA2:RESDEC.SAV
*^C
.RUN DSK RESDEC
DECTAPE DRIVE NO. = 1
PARTIAL FILES OF TYPE(1) DETECTED:
1ST. BLOK# NO. OF BLOKS
PARTIAL FILES OF TYPE(2) DETECTED:
1ST. BLOK# NO. OF BLOKS
101 17
EXIT
^C
.GET DSK RESDEC
JOB SETUP
^C
.REE
DECTAPE DRIVE NO. = 1
1ST. BLOK# = 101
1ST. BLOK# = ^C
.DIR DTA1:
231. FREE BLOCKS LEFT
FILE1 75 01-JAN-64
FILE2 09 01-JAN-64
FILE3 24 01-JAN-64
FILE4 32 01-JAN-64
FILE5 04 01-JAN-64
FILE6 04 01-JAN-64
FILE7 16 01-JAN-64
FILE8 08 01-JAN-64
FILE9 04 01-JAN-64
FILE10 06 01-JAN-64
FILE11 23 01-JAN-64
FILE12 11 01-JAN-64
FILE13 04 01-JAN-64
FILE14 04 01-JAN-64
FILE15 04 01-JAN-64
FILE16 11 01-JAN-64
FILE17 12 01-JAN-64
FILE18 15 01-JAN-64
FILE19 12 01-JAN-64
FILE20 04 01-JAN-64
FILE21 06 01-JAN-64
FILE22 55 01-JAN-64
.DIR
DIRECTORY 1000,1011 12:00 11-JAN-65
BITSF1 15 <055> 11-JAN-65
TOTAL BLOCKS 15
.
################################
# PREVIOUS DECTAPE DIRECTORY #
################################
.DIR DTA0:
216. FREE BLOCKS LEFT
ROM.MAC 11 25-DEC-64
FRED .MAC 15 25-NOV-64
TOM .MAC 04 30-NOV-64
DICK .MAC 12 16-OCT-64
HARRY .MAC 19 25
MABEL .MAC 12 17-OCT-64
DAD .MAC 55 04-FEB-64
FOO .MAC 06 25-DEC-64
ROT .MAC 04 13-MAR-64
TABLE .MAC 04 27-MAY-64
CHAIR .MAC 11 01-OCT-64
RED .SRC 06 04-APR-64
BLACK .SAV 23 31-DEC-64
BLUE .REL 04 14-AUG-64
WHITE .OPR 08 14-AUG-64
GREEN .SAV 16 25-AUG-64
YELL 04 10-NOV-64
SCREAM.MAC 04 21-JAN-64
ROCK .MAC 32 19-SEP-64
ROCK .SAV 09 20-SEP-64
INVERT.MAC 24 12-AUG-64
ROT2 .DSK 75 05-JUN-64
.
##############
# MATCHING #
##############
CLEARLY SOME OF THE FILES: FILE1,FILE2,ETC. CAN BE RENAMED
IMMEDIATELY. E.G.
FILE1 = ROT2.DSK ( 75 BLOCKS EACH)
FILE2 = ROCK.SAV ( 09 BLOCKS EACH)
FILE3 = INVERT.MAC ( 24 BLOCKS EACH)
TO SEPERATE FILES OF THE SAME SIZE, E.G. DICK.MAC AND
MABEL.MAC, THE FIRST FEW LINES OF THE FILES, FILE17 AND FILE19,
WOULD NEED TO BE TYPED OUT.
##############
# APPENDIX # ERROR MESSAGES OUTPUT ON TTY
############## ============================
MESSAGE: REASON:
-------- -------
NOTE-1 INDICATES THAT A FILE IS INFINITELY LOOPED
INTO ITSELF. I.E.THE LINK-WORDS POINTED FROM
BLOK(A)->BLOK(B)->BLOK(C)->BLOK(A) FOR
EXAMPLE. AS A RESULT OF THIS LOOPING
(ACC.3) WHICH IS USED AS A COUNTER FOR
THE NO. OF BLOCKS IN A COMPLETE FILE
WOULD REACH 575(DEC) WHICH IS IMPOSSIBLE.
RESDEC SIMPLY IGNORES THE FILE ASSOCIATED
WITH THESE BLOCKS, AND CONTINUES.
NOTE-2 CAN'T INIT DECTAPE.
NOTE-3 AS EXPLAINED ABOVE IN [3].
NOTE-4 THE LINK-WORDS WOULD SEEM TO INDICATE
THAT THERE ARE AT LEAST 40(DEC) FILES ON
THE DECTAPE(ALTHOUGH SOME WILL ONLY BE
PARTIAL FILES).IT MUST BE VERY SCRAMBLED.
IF THE USER WANTS TO CONTINUE ANYWAY, HE
COULD INCREASE THE NO. OF WORDS ASSIGNED
TO FSTFBL FROM ^D40, CHANGE THE INSTRUCT-
IONS AT COMPAR+5,AK2+1, AND INCREASE THE
NO. OF NAMES IN DNAMES.
NOTE-5 CAN'T INIT DSK.
NOTE-6 CAN'T DO AN ENTER ON DSK.
NOTE-7 RESDEC HAS RUN OUT OF DSK FILE-NAMES. THE
USER MUST HAVE FILES OF THE NAMES FILEX1,
FILEX2,ETC. ON HIS DSK AREA, OR HAS
CHANGED RESDEC.MAC AFTER HAVING PREVIOUSLY
RECEIVED THE ERROR MESSAGE, NOTE-4, AND
NOT ADDED A SUFFICIENT NO. OF NAMES TO
THE LIST IN DNAMES.
-----------------------------------------------------