youtube video of a runnning XDS Sigma mainframe with lots of nice peripherals

Lee Courtney leec2124 at
Sat Oct 31 12:37:04 CDT 2015

Pierre et al,

I posted the video you linked to. The machines on the video belonged to
George Plue, who ran a medical billing service bureau in Flagstaff AZ. They
are now located at the Living Computer Museum (LCM) in Seattle.

George originally ran the Computer Center at Anderson University in Berrien
Springs MI, and the center ran several generations of SDS the XDS Sigma
mainframes over the years. When Xerox decided to get out of the mainframe
computing business in August 1975 the market for Sigmas essentially
collapsed despite Honeywell agreeing to buy the carcass of the business.
George and a partner got into the used Sigma HW business and he maintained
a stock of HW, SW and documentation at his home in MI. More info here:

I'm unclear on when he acquired his second home in Flagstaff, but he had a
typical ranch style house in Flagstaff. The big difference being that he
had installed a significantly larger electrical feed with three-phase power
than one would find in a residence, and the downstairs family and bedrooms
were used as the machine room in the video.

I visited George in the early 2000's (I think) and at that time he had a
fully configured Sigma-9 and Sigma-8 mainframes, along with several tape
drives, and string of DASD. Yes, the machine room was strewn with
printouts, docs, partially finished projects, tapes, etc. But all the
machines worked and it was glorious. ;-)

Unfortunately George passed away a few years ago. All the HW and SW that
was in running condition was rescued by the LCM in Seattle. I know LCM has
had someone with Sigma experience working on and off on the Sigma to get it
running again. Not sure of the current status. But, that would be an
awesome time-sharing system alongside the DEC-20 they have.

There was also a group in AZ working on restoring a Sigma mainframe, maybe
some of Georges collection. He also had a complete Sigma-7 and a boatload
of Honeywell peripherals in his garage in Flagstaff. The AZ group was very
energetic, but I have not heard any updates in several years. Having worked
on CHM's first restoration, the IBM 1620, from start to finish I know its a
huge undertaking to get even a relatively straightforward machine up and

Back in the late 1990s I deinstalled a Sigma-5 at CMU that CHM acquired.
Video here:

I also learned FORTRAN on a Sigma-7 in 1973 at UT-Arlington. Cool machine.
Would *love* to hack on one again. :-)


Lee Courtney

On Sat, Oct 31, 2015 at 4:15 AM, P Gebhardt <p.gebhardt at> wrote:

> Hello list,
> spotted this video recently on youtube:
> It's a Xerox Digital Systems mainframe! Wow, I didn't know that such
> installations were still running as of 1997!
> The computer room is quite untidy. Andybody has an idea, where with was
> filmed?
> There's also a Data General minicomputer and Honeywell mainframe equipment.
> Can anybody identify the Honeywell stuff? It's Level 6000 style, but
> it's strange to me that there seems to be just this one cabinet along the
> rest of the XDS equipment. Maybe a Datanet option?
> There are *very* nice close views on running CDC disk drives using the
> 100/200MB disk packs.
> I was looking for a long time for a video actually showing how the big
> head actuator
> of these drives moves when performing data operations!
> And there are nice reel tape drives which look to me like rebadged IBM
> drives (not sure, though).
> Enjoy watching it! I did!
> Kind regards,
> Pierre
> -------------------------------------------------------------------------------
> Pierre's collection of classic computers moved to:

Lee Courtney
+1-650-704-3934 cell

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