I was going to write almost exactly this ... although the Wiki page mentions that AT&T was one of the primary customers of the System/7, AFAIK, the common control on the 1/2/3/4ESS switches was a proprietary WECo design that was highly integrated into the design of the switch itself ... in the 5E, I think the common control became a 3B20D mini and later this was replaced with an emulator of same running on some number of SPARCstations ...?
For operations support systems, I thought DEC was very popular in the Bell System; I thought many OSS ran on some modified UNIX variant or another on PDP-11 or, perhaps later, VAX which would have roughly been contemporaneous with the System/7 ... I would be really interested to know what the System/7 did at AT&T if anyone is familiar. I have a particular interested in collecting digital telephone switches ... and I too find it a real bummer that we could find ourselves in a world where there isn't one complete, functional example of such historic machines as the 1AESS, 4ESS, DMS-100, 5ESS and so on. Many completely functional examples of the old cord-boards and even the electromechanical step-by-step and crossbar switches exist in private hands but as far as I know, nobody has managed to save a complete digital CO switch of any vintage. Best, Sean On Thu, Jul 2, 2015 at 11:33 PM, Christian Gauger-Cosgrove < captainkirk...@gmail.com> wrote: > On 2 July 2015 at 17:39, Mike Ross <tmfdm...@gmail.com> wrote: > > Take the IBM System/7. Successor to the 1800, succeeded by the > > Series/1. They were *ubiquitous* - one in every telephone exchange in > > the USA, I've heard. They even made a special ruggedised version for > Being into telephony, I can say that I've not heard anything about IBM > System/7 machines being used in exchanges. I do know that the WECo ESS > exchanges did, of course, have computers. But the ESS exchange > computers were custom systems and architectures built by Western > Electric. > > The 1ESS/1AESS computer architecture is however, nearly completely > extinct. There are, I believe, only two 1ESS/1AESS switches left. One > is a partial, and non-functional exchange at the museum of > communications in Seattle; the processor is complete, and it has one > of each requisite switching frame, but it can't be used as they need > to recompile the software that runs it (which isn't possible as > they're lacking the crucial internal compiler that ran on WECo's IBM > System/3x0 machines). The other 1ESS/1AESS switch is a complete and > functional unit, still in service, last I heard. But there are plans > to scrap it and put in a modern switch in its place. Saving it would > be a difficult proposition, to say the least. > > > Regards, > Christian > -- > Christian M. Gauger-Cosgrove > STCKON08DS0 > Contact information available upon request. >