21 Sep
2023
21 Sep
'23
10:28 a.m.
Seems like rather than going through MUSIC/SP it'd be easier to just fire
up VM/CE 1.2 (which is VM/370 r6) and use CMS TAPE (which is present)
directly from the CMS UI. You can probably attach the file you've got as a
tape device; not entirely sure Hercules will like the format, but it
wouldn't hurt to try.
Adam
21 Sep
21 Sep
10:34 a.m.
New subject: IBM VM "CMS" tape format
Seems like rather than going through MUSIC/SP it'd be easier to just fire
up VM/CE 1.2 (which is VM/370 r6) and use CMS TAPE (which is present)
directly from the CMS UI. You can probably attach the file you've got as a
tape device; not entirely sure Hercules will like the format, but it
wouldn't hurt to try.
Seems like it but it isn't. Tried that the last time the issue came up and it
didn't work. "CMS TAPE" format blocks are pretty much copies of CMS disk
blocks. They are most likely 1K, 2K (or maybe 4K? - I don't recall) from just
before the VM/SP era or later, and most unlikely to be the 800 byte blocks
which are all that VM/370 R6 supports.
Regards,
Peter Coghlan.
Adam
7:40 p.m.
New subject: IBM VM "CMS" tape format
Thanks for the information so far, folks.
Now this boils down to interpreting the final CMS record for each file.
I'm not clear on how to interpret them, however. For example,
Block 10, 87 bytes:
000000 02 c3 d4 e2 d5 01 76 00 01 c1 f1 01 75 00 00 c6 |.CMSN....A1....F|
000010 00 00 00 00 50 00 08 f8 f4 12 05 12 31 00 00 01 |....&..84.......|
000020 3b 00 00 00 08 00 00 01 75 01 04 84 12 05 12 31 |...........d....|
000030 21 00 00 00 00 e4 e3 c5 40 e2 c1 e2 c6 c9 d3 c5 |.....UTE SASFILE|
000040 40 00 00 00 00 c3 c8 c5 c3 d2 f1 40 40 d7 e2 c1 | ....CHECK1 PSA|
000050 e2 40 40 40 40 c1 f1 |S A1 |
I can figure some parts of it; for example, the hex 50 at offset 0x14
apparently is the record length. I'm guessing that the 01 04 84 might
be a date code in packed BCD.
Guesses welcome !
TIA
Chuck
22 Sep
22 Sep
12:57 a.m.
New subject: IBM VM "CMS" tape format
Thanks for the information so far, folks.
Now this boils down to interpreting the final CMS record for each file.
I'm not clear on how to interpret them, however. For example,
It looks like a disk FST tweaked for writing to tape to me. Using the FST
layout in LY24-5221-2 referenced by Dennis earlier, I think maybe it might
be interpreted something like below. Apologies if I've mixed anything up
here.
? 01 76 Dunno
? 00 01 Dunno
FSTFMODE c1 f1 (Filemode A1)
FSTRECCT 01 75 (Records in file 373)
FSTCLPT 00 00 Dunno
FSTRECFM c6 ("F" fixed record format)
FSTFLAGS 00
FSTLRECL 00 00 00 50 (Record length 80 bytes)
FSTBLKCT 00 08 (800? byte block count)
FSTYEARW f8 f4 (Year written: 84)
... bit of a jump here ...
FSTDATEW 12 05 (Date: December 05)
FSTTIMEW 12 31 (Time: 12:31)
? 00 00 01 3b Dunno
FSTADBC 00 00 00 08 (should be same as FSTBLKCT for small files)
FSTAIC 00 00 01 75 (should be same as FSTRECCT for small files)
FSTNLVL 01 Dunno
FSTPTRSZ 04 Dunno
FSTADATI f8 f4 12 05 12 31 21 (Alternate date/time: 841205 12:31:21)
The next part seems mangled to me. The first part of a filename seems to be
missing.
? 00 00 00 00
? e4 e3 c5 40 e2 c1 e2 c6 c9 d3 c5 40 (incomplete filename?)
? 00 00 00 00
? c3 c8 c5 c3 d2 f1 40 40 d7 e2 c1 e2 40 40 40 40 c1 f1 (complete filename)
Regards,
Peter Coghlan
Block 10, 87 bytes:
000000 02 c3 d4 e2 d5 01 76 00 01 c1 f1 01 75 00 00 c6 |.CMSN....A1....F|
000010 00 00 00 00 50 00 08 f8 f4 12 05 12 31 00 00 01 |....&..84.......|
000020 3b 00 00 00 08 00 00 01 75 01 04 84 12 05 12 31 |...........d....|
000030 21 00 00 00 00 e4 e3 c5 40 e2 c1 e2 c6 c9 d3 c5 |.....UTE SASFILE|
000040 40 00 00 00 00 c3 c8 c5 c3 d2 f1 40 40 d7 e2 c1 | ....CHECK1 PSA|
000050 e2 40 40 40 40 c1 f1 |S A1 |
I can figure some parts of it; for example, the hex 50 at offset 0x14
apparently is the record length. I'm guessing that the 01 04 84 might
be a date code in packed BCD.
Guesses welcome !
TIA
Chuck
8:29 a.m.
New subject: IBM VM "CMS" tape format
On 9/22/23 01:57, Peter Coghlan via cctalk wrote:
It looks like a disk FST tweaked for writing to tape to me. Using the FST
layout in LY24-5221-2 referenced by Dennis earlier, I think maybe it might
be interpreted something like below. Apologies if I've mixed anything up
here.
Thank you, Peter. If additional samples of CMSN records would help
clarify things, I can supply them.
The tape itself appears to contain data from a run of SAS Institute's
(https://www.sas.com/en_us/home.html) software. I can determine that it
was run between the last months of 1984 and the early months of 1985 on
a 3083.
The client has expressed an enthusiastic interest in the content.
--Chuck
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Peter Coghlan