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From: russotto@eng.umd.edu (Matthew T. Russotto)
Newsgroups: comp.sys.mac.hardware
Subject: Re: PMMU under pre-7.0 Systems
Keywords: PMMU 68551
Message-ID: <1990Dec12.161427.6180@eng.umd.edu>
Date: 12 Dec 90 16:14:27 GMT
References: <1024@priddy.cs.utexas.edu>
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Organization: College of Engineering, Maryversity of Uniland, College Park
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In article <1024@priddy.cs.utexas.edu> rosen@cs.utexas.edu (Eric Carl Rosen) writes:
>I know that System 7.0, A/UX, and Virtual (and related products) use the
>M68851 memory managment unit, but does the generic 6.x Macintosh O/S use
>the capabilities of the PMMU in any way? If so, how?

Yes and no-- yes, they use it to mask off the top 8 bits of the address in
24-bit mode.  No, this is not any more than the HMMU that is standard with
the mac II can do.


--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
     .sig under construction, like the rest of this campus.