[Simh] OT: need tape drive solution

[Jon Elson]

Hello,

I know this is slightly off-topic, but this group might know who/what/how
to move ahead with this.

I have some old CDC Keystone tape drives.  I have verified that at least
one of them still works.  years ago at work we scrapped a Cipher 990
1600/6250 streaming tape drive that was the worst piece of crap I've
seen.  The autoloader was real flaky, but the real problem was that the
read chips had a half life of a couple months, and of course there were
9 of these chips, and they cost over $80 each.  But, on the back of the
thing was a SCSI to Pertec formatted interface converter.  So, I
saved the converter.  Well, a need to read some archival tapes came up,
so I rigged the SCSI converter up and lo and behold, it seems like
it was trying to work!  I was able to dump some file header blocks
off on a Linux system with commands like :
cat /dev/st0

or od -c /dev/st0

of course these ended as soon as they saw a file mark, that's an
end of file signal.

Well, then the damn SCSI adapter quit!  It now gets a power
on self test failure, and even though I have schematics I don't think
it is worthwhile to troubleshoot it.

Also, I'm not completely sure this converter properly supports modern
SCSI protocols, it is almost certainly SCSI-I from 1989.

So, given a PC running Linux and what really appears to be a working
CDC 92185 with formatted Pertec interface, does anybody have an
idea how to get from here to there?

It seems there are some companies selling SCSI - Pertec converters,
but I dread to think what they'd cost.  The CDC 92185 also was available
with a SCSI interface, but I've never seen one, and I did look around.

I do have a MicroVAX here with a croaked disk.  I might be able to bring
that back up, but then I'd still have the issue of getting the data from
VAX to a newer system, and the only connection I have is a serial link!
I do have the Q-bus Dilog DQ15 that ran these drives off the VAX.

So, if anybody has any good ideas or a stockpile of useful parts in their
basements, I'd like to hear about it.  If I get this running, it could be
available to recover data from other systems to help with simh
projects, too.

I know more about 9-track mag tape than most people still alive,
and wrote an almost-all software driven tape system for a Z-80 computer
about 1985.  I got a Pertec key-to-tape system from surplus and
just used the bare drive electronics.  I'd fiddle with the software
and make a backup tape, take it into work the next day and map it
using some of the programs we used there.  And, repeat until it
was a completely valid ANSI-D tape volume that VMS was happy
with.

So, I could do it all again, and the Pertec formatted interface is
actually pretty simple, but I'd rather not have to reinvent the wheel
for this if somebody already has something like this.

Jon