31 Aug
2012
31 Aug
'12
11:34 a.m.
Josh,
I'll be trying to prepare the machine as a dynamic museum display. As
part of that process, I'll be going through the existing archive to
identify what's there in detail. I have a summary list. I'll pass on a
listing of what diskettes are there as soon as I have a chance to go
through them. Before using them on the live system (assuming everything
comes back to life without too much jiggery pokery) I'll be attempting
to Catweasel the diskettes as a backup. Typically I store files in a
The PERQ disk cotnrolelr is a 765 (8272, whatever). It's normally used in
single-density 9FM) mode, and in fact double desinty is 'not certain to
work on all machines'. I have yet to find a classic PERQ (any model)
where it doesn't. However, distribution disks are likely to be single
densisty.
It is a normal controlelr using normal data rates, and the drive is a
standard SA850. You shouldn't have any problems reading the disks. Making
sense of the data is another matter. The PERQ file system is not
simple...
You might find some disks in 'interchange format'. These are actually
very similar to RT11 floopies, with the addition of an extra word (I
thin, maye 2 words) to each directoy entry gviign the exact length of the
file. RT11 actually lows you to add things to the directoty in this way,
and the PERQ did it properyl Interchange disks can be read on RT11
systems.
I misssed a footnote out of a previous message relating to the fact that
the optional 16 bit parallel interface o nthbe PERQ was DR11-C
compatible. What I inteded to say was that in development, PERQs were
booted vial this port from a VAX (of maybe even a PDP!1) fitted with a
DR11-C. The use of an RT11-cvompatible format for the 'interchange' disks
is related to this.
-tony