Date: Fri, 02 Jul 2010 11:08:37 +0200
From: Johnny Billquist <bqt at softjar.se>
Subject: Re: yet another pdp-11 in fgpa
To: cctalk at
classiccmp.org
Message-ID: <4C2DAC95.1020900 at softjar.se>
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allison <ajp166 at verizon.net> wrote:
On 06/30/2010 11:27 AM, Johnny Billquist wrote:
> > I'll reply to this one last time, and then I'll give up.
(I can't seem to keep out, can I? :-) )
I can't add too much to this regarding what
parts and what DEC
designators applied
but here are memories of the time frame.
The first multiprocessor 11/70 was built with existing hardware and a few
wire wrap and jumper mods. Memory said there were 4 total, three
inside DEC
and one at CMU that they hacked together possibly
with DEC help.
CMU did multiprocessor PDP-11s before DEC did, I think. However, they
went about it differently than the 11/74 (or whatever you want to call
it). Search for C.MMP and similar stuff on the net for more information
about CMUs multiprocessor PDP-11 projects.
The 11/74 systems were designed and built inhouse, although they might
have talked with CMU to get help, experience and whatnot. Reportedly
more than three systems were built. Rumors have it that they even had
some systems out to external customers for test, but all systems were
returned at the end of the tests (even though there is a persistent
rumor about Ontario Hydro keeping their).
I think I know of/heard of three systems that were in use inside DEC
long after the system was officially cancelled. We had, of course,
CASTOR:: which was the RSX engineering system, and which was up and
running as late as 2002 (2005?) or so. This was a 4-CPU system.
Then we had POLLUX::, which I think was a 2-CPU system. Not sure, but I
think it might have been DECnet engineering who had it. The third I've
heard about is PHEANX:: which might have been POLLUX:: after a move to
field service, and possibly also using bits and pieces from other
places inside DEC.
As far as I know, all of these systems, as well as the ones gone out on
field test, were KB11-CM cpus. So, no CIS option ever made it out of
prototypes, nor any KB11-E.
The boards from the 11/74 systems that were returned were allegedly used
in plain 11/70 machines inside DEC afterwards. They were, after all,
plug compatible with the normal 11/70 systems. The KB11-E boards would
not have been that, though.
....<snip>
I've been amused by the directions that this thread has taken over time...
My memory of the specifics of models and features is weak, as I had
moved on from DECnet-RSX to DECnet-DOS.
This website has a slightly different cut:
What I seem to remember was that CASTOR:: and POLLUX:: were the names
when they ran
those systems as dual CPUs in ZK. And they put the two together when
they wanted to run the quad.
But that could have changed over time. We were free to move node names around.
The picture on
is definitely of Brian McCarthy, a senior member of the RSX
development group and that looks like the lab I've seen (only once
that I remember)
When DECnet-RSX development was in LKG (earlier TWO) circa 1980-early
90s, ELROND:: was our dual 11/74.
When the multiprocessor project was dropped, we continued to run our
dual as the primary development timeshare.
Otherwise FS would just downgrade the system into something they
would maintain like an 11/70.
I do remember those ugly no switch panels that Field Circus installed
on all our high end systems
do they could do remote diagnostics.
Ohhh, Google finds that Bitsavers has EK-70MP-TM, PDP-11/70
Multiprocessor Manual (Preliminary)