[Simh] VAX 8200

Ethan Dicks ethan.dicks at gmail.com
Fri Mar 17 15:21:54 EDT 2017


On Fri, Mar 17, 2017 at 2:35 PM, Gary Lee Phillips <tivo.overo at gmail.com> wrote:
> Looking at what images I can find on the web, TU-80 seems correct. The one
> we had was just generally flaky, I guess. It was 1600 bpi, 2400 foot tapes,
> yes.

2400' tapes (1.5mil thickness) were standard but sometime later,
thinner (1.0 mil?) 3600' tapes came out.  I have read tape drive
instructions that say not to use those tapes in this machine.  I
wouldn't be surprised if most DEC tape drives didn't like thinner
tape.

> The MicroVAX we added later came with a TK-50 that never had any problems.

That was not a universal experience.  We had a couple of TK-50 drives
and we found them semi-reliable.  They mostly worked, but we had
occasional spectacular problems.  I had to dismantle the drive more
than once to manually rewind a tape back into the tape case.  We also
lost a few of the pickup barbs.  I have a fresh NOS one - I need to
CAD it up and experiment with various plastic films to see about
lasering some replacements.  Once the tip bends, it needs to be
replaced or it will fail at some random but inconvenient time.

-ethan


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