On 9 Date: Sat, 7 Oct 2006 18:00:13 -0400 "Bill Pechter" <pechter at gmail.com> wrote: This is urban myth appearantly. No 11/74 systems were left at customers at the end of the field tests. The most common myth is that Ontario Hydro whould have kept one, but sources there have denied it. Another myth about Ontario that I've read were about when DEC tried to convince them to change their 11/70 systems (or if it was disks) because the money they would save from lower power consuption of another system, which were replied to with a "maybe you didn't hear where I come from...". I think that actually may have been a DECUS Q&A session... And that one might be true. I don't know... Anyhow, back to the 11/74 systems... No, I remember (and probably still have the mail somewhere) that persons within Ontario denied that they kept any 11/74 systems. Also, people within DEC have firmly stated that all 11/74 systems *were* returned. Well, it is true that DEC shipped KB11-CM cards to customers to use in 11/70 systems, but that wasn't the last of it. DEC still had/have working 11/74 systems in house, and in the early 90s they did a corporate wide search for 11/74 components, I believe, to keep their systems running. (Memory a bit hazy now...) When DEC disbanded the PDP-11 OS groups, the RSX team's 11/74 (CASTOR::) were moved to Colorado Springs. The DECnet group's 11/74 (just 2 cpus, POLLUX::) were also there, and FS took over the system. Well, actually Mentec took over the system, and kept it running for another number of years. As far as I know, the system they have still exist, but last I heard they had some hardware problem with the machine, so it wasn't functional. This was maybe four years ago. Also, RSX development have finally moved off the 11/74 onto something faster. But until recent emulators on really fast hardware, the 11/74 was still the best workhorse for the development system. Which is why RSX have a very nice and functional MP implementation. :) However, appearantly the physical machine stayed inside DEC, then Compaq, and I would expect currently HP. And it sounds like there is little chance of the machine ever leaving the premises. If it is disbanded, it's destined for the scrap heap. Or atleast that's what I've been told. If someone ever manage to get it out of there, I would love to help it back to running order. I would think that most components would be the same as the 11/70. Looking at the module list, only a few modules differ. Analysing it, the changes would be in the memory bus interface (that means both cache modules and memory box bus interface). Second, the MMU and ASRB microcode is changed. But I believe that's it. That would be interesting to learn anything more about. Of course I assume you know that the PDP-11/70 and VAX-11/750 use the same memory bus, and same memory cards (with a few restrictions). Johnny