Path: utzoo!attcan!uunet!steinmetz!davidsen
From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.arch
Subject: Re: 3rd party OS
Message-ID: <11202@steinmetz.ge.com>
Date: 10 Jun 88 13:20:42 GMT
References: <3327@phri.UUCP> <63900017@convex> <321@babbage.acc.virginia.edu>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: General Electric CRD, Schenectady, NY
Lines: 35

In article <321@babbage.acc.virginia.edu> mac3n@babbage.acc.virginia.edu (Alex Colvin) writes:

| Uh...  That's Dartmouth's DTSS, or GE's Mark <some roman numeral> that

  DTSS is (was) interesting in that it is one of the systems which
allows only one processor to handle interrupts. I believe that all of
the other systems for this cpu use all processors for all functions.

  We were visiting Dartmouth back in ~1969 to see this wonder work. One
of the grad students was showing us around and was talking about how
reliable the system was if something failed. He walked over to one
processor and just pushed the "power off" button. All you heard was the
console typing a message that the cpu was gone.

  One of our group asked what would happen if that had been the control
processor. The student walked over to the control processor (after
bringing the original processor back online) and punched *its* power
off.

  The tapes stopped spinning. The printers stopped printing. Not a light
blinked anywhere in the room. Then in the distance came the chatter of
one console printing something like "service timeout on master cpu,
deconfigured. Processor C is now master." Then everything started again.

  While we were there we looked at the "RACE file." This was a monster
box full of small Mylar cards. On demand a card would be selected and
slid down to the business end, where it would be wrapped around a drum
and read as a small drum device. I believe the transfer rate was 72 bits
every 7us, or about 10 meg. This was screaming in the days of 200ms
access disks. Later GE built the 270 disk, a head per track job. They
cost a bunch but were really fast.
-- 
	bill davidsen		(wedu@ge-crd.arpa)
  {uunet | philabs | seismo}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me