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