9-Track 1/2" Tape Drive Recommendations?

Glen Slick glen.slick at gmail.com
Sat Aug 22 01:44:38 CDT 2015

On Aug 21, 2015 10:21 PM, "Ali" <cctalk at fahimi.net> wrote:
> One question: from the pictures it was not clear if this used the three
or two connector Pertec interface? I am guessing two but better to ask than
end up with a 200lb paper weight!
> -Ali

A Fujitsu M2444AC should have two 50-pin connectors for a formatted Pertec

The 'C' suffix of that model number means that it is cached. The manual
probably explains the details of how that works. I think it is basically  a
read ahead buffer during read options so if the host can't read data fast
enough to keep up with the tape movement the drive can keep moving and
reading into the cache until it fills up. That can eliminate a lot of back
and forth tape repositioning with slow hosts.

I had some Qualstar 1052 tabletop drives which were not cached. When used
with a PCTD-16 ISA bus interface controller in a PC they weren't too bad
since the PCTD-16 has its own on board buffer in the 256KB - 1024KB range.
When used with a Q-bus Pertec interface in a PDP-11 they were a lot slower
since neither the controller nor the drive had any real buffer space to
help keep the tape moving. Much slower than the same system with the cached
M2444AC instead.

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