[cctalk] Re: 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: > 00 02 c3 d4 e2 d5 01 76 00 01 c1 f1 01 75 00 00 c6 |.CMSNA1F| > 10 00 00 00 00 50 00 08 f8 f4 12 05 12 31 00 00 01 |&..84...| > 20 3b 00 00 00 08 00 00 01 75 01 04 84 12 05 12 31 |...d| > 30 21 00 00 00 00 e4 e3 c5 40 e2 c1 e2 c6 c9 d3 c5 |.UTE SASFILE| > 40 40 00 00 00 00 c3 c8 c5 c3 d2 f1 40 40 d7 e2 c1 | CHECK1 PSA| > 50 e2 40 40 40 40 c1 f1 |SA1 | 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
[cctalk] Re: 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 >
[cctalk] Re: 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. Adam
[cctalk] Re: IBM VM "CMS" tape format
> > I'll dig into it a bit today, but I believe that I'm on the right track. > > Unfortunately, the data itself is client-proprietary, so no sharing > there, sorry. > Hi Chuck, I think I pulled the files out of a similar tape image for you about 8 years ago using the CMSTAPE utility on MUSIC/SP. I'd be willing to do the same again for this one but it looks like your client won't allow it this time. You could fire up the MUSIC/SP demo system and use CMSTAPE yourself but it's probably easier to go with something along the lines of Dave's code if you are not familiar with MUSIC/SP. (I sent you an email about this earlier today but you probably haven't seen it.) Regards, Peter Coghlan.
[cctalk] Re: IBM VM "CMS" tape format
On 9/21/23 08:23, Dennis Boone via cctalk wrote: > Starting on pdf page 135 here is a description of the FST data > structures from circa 1986: > > https://bitsavers.org/pdf/ibm/370/VM_SP/Release_5_Dec86/LY24-5221-2_VM_SP_Release_5_Data_Areas_and_Control_Block_Logic_Volume_2_CMS_Dec1986.pdf > > Might help sort the CMSN block. Probably will be of help. This one was easy, comparatively. I've got yet another "mystery tape", but it has standard labels and appears to be raw data for some program (said program, of course, having disappeared). The question I don't ask myself is "exactly what will anyone do with this stuff?". Card images are mostly numeric data, arranged in fields, but no information of what the fields are, for example. Thanks, Chuck
[cctalk] Re: IBM VM "CMS" tape format
> -Original Message- > From: Chuck Guzis via cctalk > Sent: Thursday, September 21, 2023 3:39 PM > To: Dennis Boone via cctalk > Cc: Chuck Guzis > Subject: [cctalk] Re: IBM VM "CMS" tape format > > I slept on the problem a bit--good thing that I'm old; I like to sleep--and > think > that I've got it sussed out. > > Tape appears to consist of 4101 byte blocks, each with a "/02CMSx" > header; the first one seems to be "CMSF" with the intervening ones being > "CMSV" and then a final 87 byte block starting with "/02CMSN" and with > what appears to be file metadata, including the file name. The body of > the 4K+ blocks appears to be 80 character card images. Last block of each file > seems to be padded with nulls. > > I'll dig into it a bit today, but I believe that I'm on the right track. > > Unfortunately, the data itself is client-proprietary, so no sharing there, > sorry. > > What threw me was that there are 5 physical files on the tape (i.e. > blocks separated by tapemarks), so I was expecting something logical. > Silly me. > > Thanks, > Chuck Take a look at the link I pointed you too. There is code in there to list the files on the tape and copy then to a PC disk. It will work with AWS files and physical tapes. Dave
[cctalk] Re: IBM VM "CMS" tape format
> I slept on the problem a bit--good thing that I'm old; I like to > sleep--and think that I've got it sussed out. :) > Tape appears to consist of 4101 byte blocks, each with a "/02CMSx" > header; the first one seems to be "CMSF" with the intervening ones being > "CMSV" and then a final 87 byte block starting with "/02CMSN" and with > what appears to be file metadata, including the file name. The body of > the 4K+ blocks appears to be 80 character card images. Last block of > each file seems to be padded with nulls. Starting on pdf page 135 here is a description of the FST data structures from circa 1986: https://bitsavers.org/pdf/ibm/370/VM_SP/Release_5_Dec86/LY24-5221-2_VM_SP_Release_5_Data_Areas_and_Control_Block_Logic_Volume_2_CMS_Dec1986.pdf Might help sort the CMSN block. De
[cctalk] Re: IBM VM "CMS" tape format
I slept on the problem a bit--good thing that I'm old; I like to sleep--and think that I've got it sussed out. Tape appears to consist of 4101 byte blocks, each with a "/02CMSx" header; the first one seems to be "CMSF" with the intervening ones being "CMSV" and then a final 87 byte block starting with "/02CMSN" and with what appears to be file metadata, including the file name. The body of the 4K+ blocks appears to be 80 character card images. Last block of each file seems to be padded with nulls. I'll dig into it a bit today, but I believe that I'm on the right track. Unfortunately, the data itself is client-proprietary, so no sharing there, sorry. What threw me was that there are 5 physical files on the tape (i.e. blocks separated by tapemarks), so I was expecting something logical. Silly me. Thanks, Chuck
[cctalk] Re: IBM VM "CMS" tape format
> -Original Message- > From: Dennis Boone via cctalk > Sent: Thursday, September 21, 2023 4:33 AM > To: General Discussion: On-Topic and Off-Topic Posts > Cc: Dennis Boone > Subject: [cctalk] Re: IBM VM "CMS" tape format > > > Ive got a tape here from what I believe to be a VM system. The > structure is > unknown to me, although I can possibly take a stab at > it. Lots of data > between tapemarks that seems to consist of a number > of records that start > out something like this (translated from > EBCIDC): > > I think this might be the older VMFPLC (not VMFPLC2) format, used by IBM for > software distribution and other things. The format seems fairly > simple: Five character block header (x'02' 'CMS' 'N' or '0'), 800 bytes of contents. > First block is the FST for the file. Never seen a VMFPLC format tape, only VMFPLC2 or CMS TAPE command format. The main difference between CMSTAPE and VMFPLC2 is one has the FST at the start, the other at the end. I tweaked some utils from old to read and write these in AW format... https://1drv.ms/f/s!Ag4BJfE5B3onhK8KXjiJ7iUXUgRs8A?e=qS99zs which may help.. > > https://www.garlic.com/~lynn/2003b.html#42 > > Old VMFPLC may be just CMS TAPE DUMP under the covers. > > De Dave
