Path: utzoo!mnetor!uunet!husc6!linus!philabs!hunky!jww
From: jww@philabs.Philips.Com (James Wendorf)
Newsgroups: comp.sys.m68k
Subject: Re: 68020/30 based multiprocessors
Message-ID: <3372@briar.Philips.Com>
Date: 15 Mar 88 15:02:26 GMT
Sender: news@philabs.Philips.Com
Reply-To: jww@philabs.UUCP (James Wendorf)
Organization: Philips Laboratories, Briarcliff Manor, NY
Lines: 77
Summary: Summary of responses

I only received 3 responses to my earlier query about 68020/30 based
multiprocessors.  I have included them below for your information, along with
my original request.  Any further pointers would also be appreciated.  My
thanks to those who responded.

	-Jim Wendorf

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Subject: 68020/30 based multiprocessors?
From: jww@philabs.UUCP (James Wendorf)

We are seeking information on commercially available multiprocessors, based on
the 68020/30.  In particular, we are interested in machines with coherent,
uniformly accessible, shared memory.  We are looking into Computer X, but
apparently that system won't be available until the end of this year.  Has
anyone constructed a system (with caches) from commercially available boards?
I'll summarize any interesting replies for the net.

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From: harvard!ll-xn!lll-crg!lll-tis!viusys!rwb@linus (Rick)
Organization: Unisys D.A. MINIS Branch, McLean, VA
Date: 26 Feb 88 10:07:43 EST (Fri)

The Unisys 5000/85/90/95 machines are MC68020-based machines, with symmetrical
multi-processing, (not parallel).  Memory is global, with no private RAM, other
than cache, (not Megaframe mentality).  Briefly, the specs are:

5000/85 - Tower sized, up to two 25MHz MC68020 CPU's, each with 12.5MHz
MC68881, IPL proms, 64 KB cache, MMU.

5000/90 - Larger Cabinet, up to 4 12.5 MHz MC68020 CPU's, each w/ 12.5 MHz
MC68881, IPL proms, 8 Kb cache, MMU.

5000/95 - Same cabinet as 5000/90, but with up to two of the 25 MHz flavored
CPU boards.

The above systems run V.2/3, the 12.5 boards support 16 MB main, the 25
supports 64 MB.  There is a master CPU designated in these systems, which is
switch selectable.  Slave CPU's can access run queues, and other system 
structures, and can execute most system calls (~95%) so it's not the 
bottleneck you might think.

The MC68030 architecture is such that it's almost certain that there will
never be a multi-processor system based on it.

Rick Butland (rwb@viusys)

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From: sun!portal!cup.portal.com!DGD@nynex1
Date: Sat Feb 27 18:36:36 1988

Honeywell BULL Italy makes such a machine. I think it's called
the XPS-100 Model 40.  Or is that XPS 1000?

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From: amdcad!ironics@gatech (Paul Davis)
Organization: Ironics Inc. (c/o AMD)
Date:  Tue, 1 Mar 88 13:43:39 PST

You can build a 20 processor box with standard VME hardware in one
chassis.  Using some of the various approaches to inter-VMEcrate
connect you can get up to number like 100+ processors in one rack.
VME (using A32 addressing) gives 4GB of shared memory space given
the right hardware choices.  You can also get BIG (up to 1GB) memory
array boxes that can be attached.  Also, JPL has some big arrays of
020's built -- I don't know much more than they are hypercube based
and that there is some kind of commercial arrangement to sell it if it
works.
			Paul Davis, Ironics Inc., Ithaca, NY
 Reply: ironics@amdcad.AMD.COM
 Voice: (607) 277-4060

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