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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: comp.arch,comp.sys.nsc.32k,comp.sys.intel,comp.sys.m68k
Subject: Re: Question:  on-chip or off-chip MMU?
Message-ID: <8003@utzoo.UUCP>
Date: Thu, 7-May-87 12:20:47 EDT
Article-I.D.: utzoo.8003
Posted: Thu May  7 12:20:47 1987
Date-Received: Thu, 7-May-87 12:20:47 EDT
References: <5635@shemp.UCLA.EDU> <1774@im4u.UUCP>, <814@killer.UUCP>
Organization: U of Toronto Zoology
Lines: 19

> Custom MMU's are not particularly hard to build, and many companies have
> done so.  Pinnacle Systems/Logic Process Co/Whoever they are next week uses
> a custom MMU built out of 45ns or 35ns (depending on which machine) static
> rams.  The Pinnacle XL/MPulse 10 (sounds like a merger of 2 bank cards here
> in Dallas, MPact and Pulse :-) runs a 68K at 12MHz, 0 wait states, and
> according to the latest rumors the Pinnacle XL020/MPulse 20 runs a 68020
> at 16MHz, 1 wait state.  Supposedly John Bremsteller has been working on
> getting the 020 up to 25MHz with only 1 or 2 wait states.

You will forgive us, I trust, for not being too impressed...  The Sun-2,
now obsolete, ran a 68K at 12MHz with no wait states.  The early Sun-3
models, starting to look dated, run a 68020 at 16MHz with 1.5 wait states
(how in @#$%@ do they get half a wait state?...).  The Sun-3 200 series
runs a 68020 at 25MHz with circa no wait states, out of fast virtual cache.
Predictably, it's done with fast static RAMs.  This is nothing new, the
first Suns date back to circa 1980.
-- 
"If you want PL/I, you know       Henry Spencer @ U of Toronto Zoology
where to find it." -- DMR         {allegra,ihnp4,decvax,pyramid}!utzoo!henry