Xref: utzoo alt.folklore.computers:12759 comp.arch:23216
Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!hoptoad!amdcad!sono!miklg
From: miklg@sono.uucp (Michael Goldman )
Newsgroups: alt.folklore.computers,comp.arch
Subject: Re: XDS940 computer (or Xerox Sigma 9)
Message-ID: <1991Jun12.180535.19518@sono.uucp>
Date: 12 Jun 91 18:05:35 GMT
References: <1991Jun5.231450.25856@digi.lonestar.org> <13933@goofy.Apple.COM>
Organization: Acuson; Mountain View, California
Lines: 33

I worked for Comshare in the 78-79 and they were still using Xerox Sigma 9s
They had a friendly timesharing OS with one of the earliest relational
databases.  Even then, they had a hard time getting parts.  They had a dedi-
cated group of engineers scrounging the world for spare parts.  They
would get enough of them and build a new machine.  Their OS
could handle multi-CPUs but Amdahl's law prevailed and they never
used more than 3 or four together.  They were actually going to make a
new OS for it when they changed their mind and bought an IBM timesharing co.
(I mean the co. used IBM mainframes).

Then I went to work for MDSI (also in Ann Arbor) which had a very lucrative
machine tool language they ran timesharing for customers on 940s (the
founders had spun off from Comshare).  They had optimized the hell out of
that assembly language program.  They rented time on 940s from Tymshare
in Sunnyvale,
Comshare in Ann Arbor, and a French company in central France.  The little
things supported an unusually large number of customers for such an antique
machine.  They had some DEC-10s they ran for development.  They  had changed
the microcode on the DEC-10s so it would run 940 assembly code !! (Top THAT
you hackers !).  They had evaluated switching their timesharing customers to
similarly altered DEC-10s but they mis-read the data I gave them on performance
and wrongly concluded that it wsn't cost-effective.  The point became moot
when the '81-82 recession wiped out the machine tool industry in the US, and
MDSI came out with an upgrade with mind-boggling productivity improvements
for the machine tool industry which ran on a VAX (Pascal this time - they'd
learned their lesson.)

Then I moved to California.

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Michael Goldman.  "Never test for an error condition 
                   you don't know how to handle."
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++