On 8/19/2022 7:20 AM, Bob Armstrong wrote:
> On Thursday, August 18, 2022 at 2:23:16 PM UTC-7, Vincent Slyngstad wrote:
>> I have managed to rebuild, from the material on the flash drives, a
>> P?S-8 system that I believe is equivalent to the later PEPS released
>> version (8z). Sources and build trees for the older PEPS version have
>> not yet been reconstructed.
> Vince - is this version of P?S/8 available anywhere? Out of curiosity, does it still run on real hardware in addition to simh? What specific hardware is supported ? Knowing CJL I imagine he supported every PDP-8 model ever made, maybe with the exception of the 6120 DECmates - he never approved of those.
I have it online in source control, though I haven't written any web
pages about it yet for the so-much-stuff website.
is a link the PASP/PEPS distribution. There's an executable Windows
installer, and a sub-directory there with the contents unpacked for
those who don't use Windowa or want to browse it without installing it
first. (It's basically a version of SIMH and a bunch of media images
with their SIMH setup scripts. And a lot of Windows shortcuts, which I
know he spent a lot of time on, but that I never used.)
Next door in https://svn.so-much-stuff.com/svn/trunk/pdp8/cjl/pqs8/
are build trees for 8u and 8z. The 8u directory doesn't do anything
yet. The 8z directory has a start toward a cross-assembly build, but
that isn't finished either.
In the 8z/simh directory and sub-directories is the actual build, which
consists of several scripts run under SIMH to perform a native build
from source, then patch the binaries to match the PEPS distribution of
8z. This working build is for DECtape.
The PEPS distribution contains a "new" and an "old" release for RK05 and
for DECTape. The DECtape versions have been patched to rewind
differently than the sources, which was supposed to be an optimization
for the SIMH environment. (Effectively it simulates a keyboard ^R
"rewind" before each prompt, if I'm remembering correctly.)
While the code is CPU agnostic, even to the point of working on
DECmates, the system head is usually TC01/TC08 DECtape. P?S-8 supports
8 units in the system driver, so you get a pretty tricked out system for
that device. Unfortunately, support for other devices is mostly lame.
The drivers are there and installed, but the only utilities that know
how to load and use them are meant to migrate things to and from the
The exceptions are the console and line printer, which are system calls
and so supported on every system head. Alas, not so the paper tape
reader. (CJL clearly thought paper tape to be awful, but really loved
Files on P?S-8 are also "odd" to folks who are used to OS/8 or the like.
They are always 4K. Text files have line numbers, and the built-in
editor allows you to retype, insert, and delete lines, much as you would
expect from a BASIC interpreter. The assembler converts from one to
several such files into a 4K binary file. Doing anything with larger
files or non-system devices is quite baroque, and really requires
knowledge of the P?S-8 internals.
There are two directories. The DIRectory contains system programs, and
files are generally created there only at install time, by directly
editing the media. The CATalog contains all the user's 4K files, and is
where the user is expected to work.
> It might not be widely known, but CJL also contracted with Intersil to write IFDOS, which was the official disk OS for the Intercept systems. Have you found any of that? The Intercepts were 6100 based machines that were largely PDP-8 compatible. Most of the standard DEC paper tape software would work w/o modification, but the only mass storage option was a floppy disk that wasn't RX8 compatible. I have copies of the IFDOS manual, but I've never seen any of the actual software for it.
> I always wondered if IFDOS was simply an early version of P?S/8. It'd be great to see that preserved too.
IFDOS is indeed an earlier version of P?S-8. There are files for an old
floppy version, but I'm not sure if it is exactly IFDOS or something
later. I'm also not sure how complete it is.