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From: cswarren@gershwin.berkeley.edu (Warren Gish;269A LSA;x3-9219)
Newsgroups: comp.sys.mac,comp.sys.mac.programmer
Subject: Re: System 7.0 , virtual mem and 3rd party '030s
Keywords: System 7.0
Message-ID: <24510@agate.BERKELEY.EDU>
Date: 17 May 89 06:35:28 GMT
References: <813@cbnewsc.ATT.COM>
Sender: usenet@agate.BERKELEY.EDU
Reply-To: cswarren@gershwin.berkeley.edu.UUCP (Warren Gish)
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Organization: University of California, Berkeley
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In article <813@cbnewsc.ATT.COM> fjo@cbnewsc.ATT.COM (frank.j.owen) writes:
<Well, the subject (hopefully) outlines my question:
<System 7.0 sounds great. What about 3rd party '030 upgrades.
<(The one from TSI comes to mind.) These have MMU capability, so
<should (in theory) be able to do virtual memory.
<
<I think there are also adapter boards that plug into the '020 socket
<of a MacII to allow the substitution of an '030. (I think the cost
<is much greater than just getting the MMU, so I doubt whether anyone
<would actually DO this.)

Okay, Chip Freaks, set me straight!

Eons ago in one of the trade journal descriptions of the original
MacII it was stated that, with the stock HMMU, a single wait state is
incurred for memory accesses; but when the PMMU is installed and used
in virtual memory applications, yet another wait state is introduced.

The MC68030 has a reputation for eliminating one wait state under
the current System 6.0.  What about under A/UX and under System 7.0's
virtual memory?  Does/will the 68030 Macs then use 2 wait states fewer
than a PMMU-equipped MacII?

<
<So... If you have a non-Apple '030 in your box, will you be able
<to utilize the Virtual memory built into system 7.0?
<-- 
<Frank Owen (fjo@ttrdf)  312-982-2182
<AT&T Bell Laboratories 
<5555 Touhy Ave., Skokie, IL  60077
<PATH:  ...!att!ttrdf!fjo

Warren Gish
Consultant for Biology
University of California
Berkeley, CA 94720
(415) 643-9219
cswarren@violet.berkeley.edu
cswarren@ucbviole.bitnet