Re: LINC Tapes

21 views
Skip to first unread message

Michael Thompson

unread,
Jul 24, 2017, 12:52:18 PM7/24/17
to Warren Stearns, PDP-12 Restoration Project
Warren send the images of the LINC tapes to me. I have been working on a Windows program that can read the LINC tape images.

DEC-12-SEZB-U1_PART_1_LAP-6_DIAL_MS.linc has the directory at block 343, It is usually at 346. I will dig a little further to see if three blocks are missing from the image.

DEC-12-SEZB-U2_PART_2_LAP-6_DIAL_MS.linc
NAME          BN BLKS

PIP       B 0247 0021
MARK12    B 0240 0007
BUILD     S 0150 0070
ASSEM1    S 0470 0045
ASSEM2    S 0535 0050
ASSEM3    S 0102 0046
EDITOR1   S 0605 0037
EDITOR2   S 0014 0066
PXDXSRC   S 0644 0021
PRINTMS   S 0665 0015
LOADER    S 0702 0025
MILDRED   S 0727 0035

decus_12-7_8.linc
NAME          BN BLKS

PIP       B 0747 0021
BINDEC 1  S 0470 0003
BINDEC 2  S 0473 0003
BINDEC 3  S 0476 0003
BINDEC 4  S 0501 0003
BINDEC 5  S 0504 0005
BINDEC 7  S 0245 0004
BINDEC 8  S 0511 0004
BINDEC 9  S 0243 0002
DECBIN 1  S 0240 0003
DECBIN 2  S 0536 0004
DECBIN 3  S 0234 0004
DECBIN 4  S 0515 0004
BINOCT 1  S 0233 0001
BINOCT 2  S 0524 0002
OCTBIN 1  S 0231 0002
OCTBIN 2  S 0521 0002
SERINDEX  S 0226 0003
DBLFLT3   S 0542 0077
          B 0206 0011
DBLFLT3S  S 0646 0034
DBLFLT    S 0175 0011
          B 0132 0004
TELETYPE  S 0076 0004
DBLFLT1   S 0136 0037
          B 0222 0004
DBLFLT1S  S 0117 0012
DIALV2    S 0266 0002
DAYCOM    B 0641 0005
TESTDATA  B 0000 0046
GREENSLV  B 0106 0005
DBL3GO    S 0526 0004
DBL3GOY   S 0104 0002
DBL3GOZ   S 0102 0002
DBLFLT4   S 0702 0045
          B 0062 0006
DBL4GO    S 0255 0003
D4RULES   S 0070 0006
DECUS     S 0263 0001
NO. 12-7  S 0262 0001
AND 12-8  S 0261 0001
6-6-71    S 0260 0001

decus_12-24_30_er_focal_overlays.linc
NAME          BN BLKS
PIP       B 0247 0021
MARK12    B 0470 0007
FOCAL-12  B 0477 0026
$THRUF0   S 0224 0012
          B 0243 0004
$TEXT     S 0236 0001
          B 0237 0004
FOCL-12K  S 0213 0011
          B 0525 0027
$DEVICE   S 0207 0004
          B 0203 0004
$CHARSIZ  S 0150 0001
          B 0143 0004
$DATAPLT  B 0554 0004
$PLOT     S 0170 0013
          B 0560 0026
$SNS      S 0166 0002
          B 0162 0004
$LP08     S 0160 0002
          B 0154 0004
$RELAY    S 0151 0003
          B 0606 0004
$ECHO     S 0147 0001
          B 0612 0004
$ECHOFN   S 0616 0002
          B 0115 0026
$ECHOEX   B 0620 0004
TDUMP     S 0014 0045
          B 0104 0011
$DTOA     S 0634 0002
          B 0061 0004
LDSCUB    B 0636 0041
PUMPKIN   B 0677 0024

decus_12-25_11_15.linc
NAME          BN BLKS
SCRMBL    S 0266 0002
          B 0264 0002
QANDA-C   S 0212 0020
          B 0207 0003
HISTO12   S 0513 0040
          B 0553 0011
FPP2      S 0470 0001
          B 0564 0007
ODTAPE    S 0172 0015
          B 0165 0005
RATE      B 0156 0007
NRATE     B 0573 0007
STRINGS   B 0151 0005
FRACUS    S 0240 0024
          B 0232 0006
PIP       B 0472 0021
FRACUS-G  S 0602 0024
          B 0143 0006
QANDA+    S 0123 0020
          B 0073 0003
SPY+      S 0104 0017
          B 0076 0006
KWANDA    S 0051 0022
          B 0630 0003
KWDEMO    S 0626 0002

decus_12-46_54.linc
NAME          BN BLKS
STRINGS   S 0171 0031
          B 0263 0005
PIP-1600  S 0477 0077
          B 0252 0011
CREF12    B 0243 0007
PIP       B 0222 0021
MARK12X   S 0120 0051
          B 0470 0007
MILDREDB  S 0062 0036
FRED-BIG  S 0576 0037
COMS-BIG  S 0061 0001
          B 0046 0013
QUIP      B 0635 0016
LINO18    S 0045 0001
LINO18A   S 0004 0041
LINO18B   S 0653 0050
LINO18C   S 0723 0042
INFO      S 0003 0001

decus-12-80.linc
NAME          BN BLKS
FOCAL-RT  S 0142 0026
          B 0242 0026
RD-WRI    S 0237 0003
FOCLDR    S 0233 0004
          B 0231 0002
PIP       B 0477 0021
PROGRAM2  B 0520 0004
DEMO      S 0222 0004
          B 0226 0003
PROGRAM0  B 0470 0004
RELAY     B 0474 0001
LOOMPRNT  B 0475 0002
RTPATCH   S 0174 0001
$DEVICRT  S 0170 0004
          B 0216 0004
FOCLDR2   S 0212 0004
POINTS    B 0205 0005
POGEN     B 0201 0004
POGET     B 0175 0004

DEMO_12_NUMBER_1_Jan_4_72.linc
NAME          BN BLKS
OMAGSPY   S 0160 0037
DRAW12    S 0540 0006
KALIED    S 0520 0001
REMAKE    B 0141 0017
BALLOON   B 0507 0005
H-DIAL    S 0514 0001
H-FRQANA  S 0515 0002
H-FREQ12  S 0521 0002
H-B.BALL  S 0517 0001
H-ECHASK  S 0523 0002
H-DAYCOM  S 0527 0001
H-STPWCH  S 0530 0001
H-DRAW12  S 0531 0002
H-SOLACE  S 0533 0001
H-CLOCK   S 0534 0001
H-BASMEM  S 0561 0001
H-MAGSPY  S 0137 0002
H-A-DTST  S 0136 0001
DATA12    S 0244 0017
ECHASK    S 0535 0003
H-DATA12  S 0621 0003
MARK12    B 0127 0007
WOLFT     S 0470 0001
LINE      S 0501 0001
          B 0502 0002
PIP       B 0673 0021
EX.PROG.  S 0525 0001
AD DEMO   S 0526 0001
          B 0471 0003
KW12SUBC  S 0474 0005
LOADER    S 0635 0002
          B 0557 0002
INITLIZE  S 0102 0017
          B 0546 0003
SEG0      S 0637 0034
          B 0613 0006
SEG1      S 0044 0036
          B 0551 0006
STPWCH    S 0217 0025
FRQANA    S 0562 0031
INDEXSRC  S 0263 0005

dial_v2_source_tape_dec_1970.linc
NAME          BN BLKS
PIP       B 0251 0017
MARK12    B 0470 0007
PXDXSRC   S 0031 0021
PRINTMS   S 0105 0015
PIP2      S 0511 0071
LOADERST  S 0237 0012
PIP1      S 0171 0046
PIP4      S 0602 0056
PIP3      S 0122 0047
SAVBINST  S 0660 0015
DIALV2B   S 0104 0001
EDITORV2  S 0676 0077
APNPTRV2  S 0477 0012
FCOMSV2   S 0064 0020

MAINDEC-12-D7AC-U0_pdp12_diagnostics.linc
NAME          BN BLKS
PIP       S 0604 0001
          B 0251 0017
MARK12    S 0603 0001
          B 0470 0007
RIMLDR    S 0605 0001
          B 0477 0003
BINLDR    S 0606 0001
          B 0502 0003
CBL       S 0607 0001
          B 0505 0003
CBH       S 0104 0001
          B 0245 0004
ADDRSLO   S 0612 0001
          B 0510 0003
ADDRSHI   S 0103 0001
          B 0241 0004
ADDRS12   S 0611 0001
          B 0513 0002
RANISZ    S 0101 0001
          B 0515 0005
RANJMP    S 0102 0001
          B 0235 0004
JMPJMS    S 0100 0001
          B 0522 0004
JMPSELF   S 0610 0001
          B 0233 0002
MEMDATA   S 0613 0001
          B 0231 0002
INST1     S 0614 0001
          B 0526 0013
INST2     S 0077 0001
          B 0217 0012
INST2A    S 0726 0001
          B 0203 0014
INST2B    S 0602 0001
          B 0541 0006
LPEXTM    S 0202 0001
          B 0547 0015
PRINTEC   S 0174 0001
          B 0123 0006
CPTST1    S 0712 0001
          B 0564 0004
CPTST2    S 0713 0001
          B 0146 0021
CPTST3    S 0725 0001
          B 0131 0015
TTY1      S 0714 0001
          B 0570 0007
TTY2      S 0715 0001
          B 0615 0013
EXTMC     S 0717 0001
          B 0113 0006
EXTAT     S 0720 0001
          B 0644 0010
EXTMC12   S 0001 0001
          B 0074 0003
TC12 I    S 0770 0001
          B 0041 0021
TC12 II   S 0771 0001
          B 0727 0015
TAPEDATA  S 0767 0001
          B 0107 0004
ADTST     S 0761 0001
          B 0034 0005
RELAYTST  S 0762 0001
          B 0706 0004
DISPTST   S 0763 0001
          B 0030 0004
KW12A     S 0772 0001
          B 0006 0021
ONOFF     S 0765 0001
          B 0722 0003
CB12      S 0773 0001
          B 0003 0003
TAPEXER   S 0173 0001
          B 0665 0010
SNSDIS    S 0701 0004
          B 0675 0004

MAINDEC-12-D8GA-U0_OPTIONAL_SYSTEM_DIAGNOTIC_6-3-70.linc
NAME          BN BLKS
PIP       S 0042 0001
          B 0251 0017
MARK12    S 0041 0001
          B 0470 0007
RIMLDR    S 0037 0001
          B 0477 0003
BINLDR    S 0040 0001
          B 0502 0003
DB12      S 0250 0001
          B 0505 0005
DC04      S 0247 0001
          B 0515 0011
LPEXTM    S 0651 0001
          B 0146 0015
EAE3A     S 0530 0001
          B 0131 0015
PECITRE   S 0555 0001
          B 0534 0007
PECITIT   S 0245 0001
          B 0207 0011
PECITDRT  S 0246 0001
          B 0543 0012
PECITDT   S 0512 0001
          B 0201 0006
DC02F     S 0526 0002
          B 0163 0011
DC02E     S 0531 0001
          B 0571 0006
EAE3B     S 0532 0001
          B 0615 0014
CALCOMP   S 0533 0001
          B 0121 0010
TC12F     S 0577 0001
          B 0631 0010
DP12A     S 0600 0001
          B 0105 0014
PWRFAIL   S 0601 0001
          B 0641 0003
KW12BC    S 0602 0001
          B 0644 0005
HSRDPUN   S 0244 0001
          B 0603 0012
DF32DD    S 0243 0001
          B 0220 0021
DF32DL    S 0242 0001
          B 0556 0013
RF08DD    S 0241 0001
          B 0060 0013
RF08MD    S 0513 0001
          B 0174 0005
LINEPNTR  S 0514 0001
          B 0054 0004
CARDREAD  S 0043 0001
          B 0703 0006


On Sun, Jul 23, 2017 at 10:31 PM, Warren Stearns <warren_...@yahoo.com> wrote:
On 7/23/2017 6:46 AM, Michael Thompson wrote:
Tape images?


9 original DEC tapes:   all the DEC-12, decus_12, and MAINDEC-12

2 not original:    DEMO_12_NUMBER_1
                        dial_v2_source_tape.

warren



--
Michael Thompson

Jack Rubin

unread,
Jul 24, 2017, 12:58:04 PM7/24/17
to Michael Thompson, Warren Stearns, PDP-12 Restoration Project

Please provide details on tape imaging and image reading.

Thanks,

Jack

--
You received this message because you are subscribed to the Google Groups "PDP-12 Restoration Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pdp+uns...@d.umn.edu.

Michael Thompson

unread,
Jul 24, 2017, 2:55:57 PM7/24/17
to Warren Stearns, PDP-12 Restoration Project
I was able to read the first tape by zeroing the first three blocks.
 
DEC-12-SEZB-U1_PART_1_LAP-6_DIAL_MS.linc
NAME          BN BLKS
PIP       B 0247 0021
MARK12    B 0470 0007
PIP1      S 0477 0056
PIP2      S 0151 0076
PIP3      S 0076 0053
PIP4      S 0555 0040
PIP5      S 0615 0066
FILECOMS  S 0016 0054
CREF12    S 0703 0051
GENASYS   S 0003 0013 



--
Michael Thompson

Michael Thompson

unread,
Jul 24, 2017, 2:58:26 PM7/24/17
to Jack Rubin, Warren Stearns, PDP-12 Restoration Project
Jack,

Warren wrote a dumprest program for the PDP-12 and archived the UMN tapes in .linc files.
I am working on a program that can read .linc files, display a directory, extract source and binary files, display blocks, etc.
--
Michael Thompson

Jack Rubin

unread,
Jul 24, 2017, 3:52:56 PM7/24/17
to Michael Thompson, Warren Stearns, PDP-12 Restoration Project

I’m guessing the dump program similar to David G’s DUMPREST for the 8? Is your display program ready to be shared? I’m always interested in learning more  about your tools as a way to learn more about the tape internals.

 

Thanks,

Jack

Warren Stearns

unread,
Jul 25, 2017, 12:20:39 AM7/25/17
to p...@d.umn.edu
On 7/24/2017 1:52 PM, Jack Rubin wrote:

I’m guessing the dump program similar to David G’s DUMPREST for the 8? Is your display program ready to be shared? I’m always interested in learning more  about your tools as a way to learn more about the tape internals.

Warren send the images of the LINC tapes to me. I have been working on a Windows program that can read the LINC tape images.

 

DEC-12-SEZB-U1_PART_1_LAP-6_DIAL_MS.linc has the directory at block 343, It is usually at 346. I will dig a little further to see if three blocks are missing from the image.

All the .linc tape images I sent are clean LAP-6/DIAL images. 
They are 262,150 bytes long.
The directory starts at 117,760 bytes (1CC00h).
It has  (EF 0B EF 0B) x 4 for the 0th entry.
(EF 0B  EF 0B is octal 5757 5757 or '////')
(FF 0F              is octal 7777 or '??')

See attached hex dump of 1st 8 directory entries.

For file format, see below.


 

On Sun, Jul 23, 2017 at 10:31 PM, Warren Stearns <warren_...@yahoo.com> wrote:


9 original DEC tapes:   all the DEC-12, decus_12, and MAINDEC-12

2 not original:    DEMO_12_NUMBER_1
                        dial_v2_source_tape.

Like David G's .linc tape images, they have 3 words appended to the end.

    1st appended word:   block size  (s/b 256 for LAP-6/DIAL tape images).

    2nd appended word:    12-bit two's complement of the number of leading blocks
                (these blocks have negative block numbers per examining MARK12 source).
               Since Dave G. used a BeadleBone-Black(IIRC) with a TU-56 with G888 amplifier cards (outputs logic                     level tape channel signals), he was able to read these.
                The PDP-12 TC-12 can NOT read these and hence, this word is always 0000 on my captured images.
                (i.e.files start with block 0, not the leading garbage blocks).

    3rd appended word:    12-bit two's complement of the number of trailing blocks
                 (these have continuing sequential block numbers).
                The PDP-12 TC-12 does NOT read these and hence, this word is always 0000 on my captured images.

I would think that all of trailing blocks could be read by the TC-12, but my 'dumplt' program does not read them.
I need to do more work on it as it is NOT correctly handling bad blocks (UMD has 2 tapes that I could not read).

I will probably create a low-level format that preserves block numbers, data from bad read, etc.  Then process it
into existing 'linc' images. 
There's been much discussion on mag tape imaging and keeping all meta-data (block lengths, EOF records, bad blocks, etc).  Lots of formats, all seem to have issues.

The first version of 'dumplt' reads one block at a time.
It works, but is slow:
     15 minutes to read a 128 word, 1536 block 'OS/12' linctape.
       8 minutes to read a 256 word  512 block 'LAP-6/DIAL' linctape.

I made a version that is buffered (both versions run in 4K). that read about 25 128 word.
It works, but is even worst on bad blocks or detecting the end of tape.
It's much faster, around 4 minutes instead of 15.

Dave's images are not consistent. 
They have fewer or more trailer blocks than the 3rd appended word implies.
The second word is seems correct, but the number of leading blocks varies.

I assume there are different versions of MARK12 that generate different number of leading blocks.
   
warren

hex_dump_of_first_8_directory_entries.txt

Vincent Slyngstad

unread,
Mar 27, 2022, 2:59:45 AM3/27/22
to UMD PDP-12 Restoration Project
I've been working a little on utilities to get files on and off of LINCtape images (mostly off, so far).

Are there tape images online somewhere I can look at to beef up my tools and image archive?

Thanks,

Vince

Michael Thompson

unread,
Mar 28, 2022, 9:35:54 AM3/28/22
to Vincent Slyngstad, UMD PDP-12 Restoration Project

--
You received this message because you are subscribed to the Google Groups "UMD PDP-12 Restoration Project" group.

To unsubscribe from this group and stop receiving emails from it, send an email to pdp+uns...@d.umn.edu.
To view this discussion on the web visit https://groups.google.com/a/d.umn.edu/d/msgid/pdp/a9658db4-ce66-4e26-af0f-5e370a89e0f7n%40d.umn.edu.


--
Michael Thompson

Vincent Slyngstad

unread,
Mar 28, 2022, 9:52:23 AM3/28/22
to UMD PDP-12 Restoration Project, michael.9...@gmail.com, UMD PDP-12 Restoration Project, Vincent Slyngstad
Thanks!  Those are the ones I knew about.

Vince

Michael Thompson

unread,
Mar 28, 2022, 10:04:54 AM3/28/22
to Vincent Slyngstad, UMD PDP-12 Restoration Project
My Windows based tool works pretty well for listing the directory of a LINC tape image and extracting text files. We could compare results to test your program.
--
Michael Thompson

Vincent Slyngstad

unread,
Mar 28, 2022, 10:16:24 AM3/28/22
to UMD PDP-12 Restoration Project, michael.9...@gmail.com, UMD PDP-12 Restoration Project, Vincent Slyngstad
I've got similar functionality, though I'm still a little hazy about the rules for locating the directory.  I think I left off working when I could read tape images with the directory at 343 or 346, but still not all the tapes were working.  I felt like I needed to research more about the older LAP versions or something, rather than hack around looking hither and yon for a directory I could understand.

My stuff is written (in Perl) to be an '8tools' thing.  It operates by providing a tool to convert the tape images to a standard block format, and also tools to then look for file system structure (dial, os8, etc) in that.  The file system tools don't care if the image originally came from LINCtape, DECtape, RK05, SerialDisk, etc.

Vince

Michael Thompson

unread,
Mar 28, 2022, 10:28:41 AM3/28/22
to Vincent Slyngstad, UMD PDP-12 Restoration Project
Mine isn't so intelligent. On mine you have to click on a radio-button to tell it what type of image you have, the block size, word size, etc.

I added an octal dump tool that also interprets the data in 6-bit DEC and 8-bit ASCII. That has proven to be very useful because, as you said, the rules for tape sizes and format changed over the life of the systems.

--
Michael Thompson

Michael Thompson

unread,
Mar 28, 2022, 10:45:19 AM3/28/22
to Vincent Slyngstad, UMD PDP-12 Restoration Project
image.png
image.png
image.png
--
Michael Thompson

Peter Peterson

unread,
Apr 27, 2022, 5:20:55 PM4/27/22
to Michael Thompson, Vincent Slyngstad, UMD PDP-12 Restoration Project
Hi all,

Finally crawling out of a hole of work and a family emergency.

Dawson or Mike, do either of you know what happened to the tape images Warren made from our tapes at UMD? Those might be interesting to look at.

I don't know if we have copies of those here, but I believe he managed to dump what we had.

Peter

--
You received this message because you are subscribed to the Google Groups "UMD PDP-12 Restoration Project" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pdp+uns...@d.umn.edu.
To view this discussion on the web visit https://groups.google.com/a/d.umn.edu/d/msgid/pdp/CAH1BU%3D9aAHTGEJE1My2R2697%3D_GQv9YbfVL5eHG2Tn6E7rneuw%40mail.gmail.com.


--
Peter A. H. Peterson, Ph.D. (he/him)
Assistant Professor
Department of Computer Science
University of Minnesota Duluth

Michael Thompson

unread,
Apr 27, 2022, 7:02:27 PM4/27/22
to Peter Peterson, Vincent Slyngstad, UMD PDP-12 Restoration Project
I will look for copies. If I don't have images of the tapes, then Doug might.
--
Michael Thompson

Peter Peterson

unread,
Apr 28, 2022, 1:10:41 PM4/28/22
to Michael Thompson, Vincent Slyngstad, UMD PDP-12 Restoration Project
Sounds great -- thanks, Mike.

Peter Peterson

unread,
Apr 28, 2022, 1:44:38 PM4/28/22
to Michael Thompson, Vincent Slyngstad, UMD PDP-12 Restoration Project
Hi all,

Julian pointed me to our archive of tapes. Vince, I'll zip them up and email them to you directly.

Thanks Julian!

Peter
Reply all
Reply to author
Forward
0 new messages