21 Sep
2023
21 Sep
'23
8:23 a.m.
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_R…
Might help sort the CMSN block.
De