Ethan Dicks ethan.dicks at usap.gov
Tue Oct 21 17:53:00 CDT 2008

On Tue, Oct 21, 2008 at 06:35:39PM -0400, Charles H Dickman wrote:
> Anybody here have direct experience with RTS-8?

Some, from 20+ years ago.
> I have a PDP-8/e, some digital and analog I/O cards and have toyed with 
> the idea of trying to get RTS-8 running to control something (not sure 
> what exactly).

I did not get that far into it - I built it on an -8/m at Ohio State
(they used to have a pair of /ms to collect and analyze data from a
mass spectrometer for the purpose of looking for performance enhancing
drugs in horse urine for the state racing commission), and on my own
-8/a w/KT8A and 128kW of MOS mem.

Mostly, I have built RTS-8 per the instructions, including an example
program or two, and did get the OS/8 task working on it with little
effort.  I never attempted to do any "real" work or development on it,
since, at the time, it was to me a curiosity, and didn't give me
anything I couldn't already get from an ordinary OS/8 system.  If I
could have run two or more OS/8 tasks (which I do not think is
possible by default), that would have made it more interesting to me.

If you have all the sources and the contemporary docs, my recollection
is that everything builds and runs as documented.  I do not remember
any 'gotchas' or any undocumented tricks.  ISTR that it was mostly
useful as a starting point for your own development.  There were
a few sample programs in the docs to demonstrate how to work with
co-routines and how to pass messages between tasks, but essentially
no ready-to-roll-out applications for it.  I also have a memory that
by the time v3 came out, the expected platform was an -8/a w/more than
32kW, but that was mostly so you could run an OS/8 task with the
full 32kW for it and still have some core left over for RTS-8 itself.
If you can get away with 16kW or 24kW for OS/8 (no ADVENT for you!),
then it should run fine on a maxxed-out -8/e.  If you don't care
about running an OS/8 task while your code is frobbing your I/O cards,
then memory is less of an issue.

> I think DECnet for the PDP-8 requires RTS-8 too.

I believe that is the case, but until this year, I hadn't ever run
across more then mere mention of DECnet-8.  Only recently, I have
at least found (on bitsavers or one of the other major repositories)
some docs on it.  I looked for it 22 years ago, but was unable to
trace it down then.

I don't believe it does much more than simple message and file
passing, and I don't think it's compatible with DECnet on any
other platform, but it _is_ vendor-supplied basic networking
for an otherwise ignored architecture.


Ethan Dicks, A-333-S     Current South Pole Weather at 21-Oct-2008 at 22:30 Z
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Ethan.Dicks at usap.gov            http://penguincentral.com/penguincentral.html

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