31 Aug
2012
31 Aug
'12
1:17 p.m.
On Fri, Aug 31, 2012 at 11:34 AM, Tony Duell <ard at p850ug1.demon.co.uk>wrote:
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...
I've written a utility (in C#) that can read, navigate, and copy files
from POS filesystem images, both for hard disk images
(of 12 or
24-mb SA4000s currently, since I have no images of other drive types) and
floppy disk images. Someday I'll add write support, since it'd be very
useful for use with PERQemu. It should be pretty trivial to port to
whatever language your preference is (or it can run under Mono on Unices.)
It does not support RT-11 interchange format disks (yet), but that may be
better supported by another utility already out there.
Let me know if you want a copy (I really really do need to update my PERQ
website to provide this stuff...)
- Josh
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