Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!umich!samsung!usc!rutgers!bellcore!flash!mo
From: mo@flash.bellcore.com (Michael O'Dell)
Newsgroups: comp.sys.mac.hardware
Subject: Re: Why no VM on a 68K? (was: Re: Why 68000?)
Keywords: MMU virtual memory Sys. 7.0 low-end
Message-ID: <20123@bellcore.bellcore.com>
Date: 17 Feb 90 21:22:38 GMT
References: <1990Feb11.154304.19943@smsc.sony.com> <3919@hub.UUCP> <10223@hoptoad.uucp> <1990Feb15.155556.5319@uncecs.edu> <19472@dartvax.Dartmouth.EDU> <502@taniwha.UUCP>
Sender: news@bellcore.bellcore.com
Reply-To: mo@flash.UUCP (Michael O'Dell)
Organization: The Center for Virtual Reality
Lines: 21

Sorry folks, but the first Sun-1 cpu board did NOT do demand-paged
virtual memory because it had 1 68000.  The upgraded board,
which became the basis of the Multibus-1 Sun-2 machines had
a 68010 on it, which was a 68000 which could fault and restart.

I think the first commercial machine I know of using the dual processor trick
to do demand paging was an Apollo, but the Masscomp machines also used
the trick, and I don't remember who was out first.  Masscomp was out early,
however, with a demand paged system system running Unix and twin 68Ks.
FOr its time, the Masscomp box with all the slick A/D and D/A hardware
and software made one hell of a demo!

	-Mike


	-Mike O'Dell

"I can barely speak for myself, much less anyone else!"
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The Center for Virtual Reality --
"Solving yesterday's problems tomorrow!"