PDP-11/74 MP

Johnny Billquist bqt at update.uu.se
Sun May 17 06:18:51 CDT 2015

On 2015-05-17 00:59, Christian Gauger-Cosgrove wrote:
> On 15 May 2015 at 16:14,  <Paul_Koning at dell.com> wrote:
>> A correspondent just pointed me to a nice collection of photos of a (the?) 11/74 MP system:
>> http://oboguev.livejournal.com/2696291.html
> I heard it was supposedly called Phoneix (PHEANX as DECnet node name).
> And yes, that is one of the 11/74 systems, and that is the RSX-11/M+
> group's machine, from what I recall of previous discussions of it.

Sortof. It's from Dave Carroll, and the 11/74 at Colorado Springs. This 
was PHEANX. It was after the RSX group didn't exist anymore, and whay 
gathered what remained of 11/74 systems into the Colorado Springs site, 
since that is where all PDP-11 stuff went finally at DEC, before it 
moved over to Mentec.

> It's interesting to see the different names that the 11/74 could have
> had as a product painted on the machine(s). I also recall somewhere
> that one of the other names it could have had was 11/72. (I think for
> a dual processor configuration?)

I've seen/heard some reference to 11/72, but all the papers from DEC on 
PDP-11 MP systems called them 11/74 that I can remember. No matter how 
many CPUs was in the system.

> It's neat that the newest version of RSX-11/M+ still supports the
> 11/74 (try it on E-11).

It does indeed work. MIM is available for public access. Telnet to 
mim.update.uu.se, login as guest with password guest.
Run RMS, and notice the CPA, CPB, CPC and CPD on the memory page.
However, E11 have some bugs, so it don't run stable with more than one 
CPU online, so I normally only have one CPU running.


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