*BSD News Article 56259


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From: sfkaplan@cs.utexas.edu (Scott Frederick Kaplan)
Newsgroups: comp.unix.bsd.netbsd.misc
Subject: Re: NetBSD on a Mac SE?
Date: 7 Dec 1995 07:54:39 -0600
Organization: CS Dept, University of Texas at Austin
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References: <49m0u3$lvl@huron.eel.ufl.edu> <MICHAELV.95Dec2231953@MindBender.HeadCandy.com> <MICHAELV.95Dec6223740@MindBender.HeadCandy.com>
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Michael L. VanLoon (michaelv@MindBender.HeadCandy.com) wrote:
: But to interject more possibly corrupt memory into this, I don't
: believe the SE/30 can go that high.  Wasn't there a hard 13MB limit on
: the older Macs because of the way the memory was arranged?  Maybe that
: was just a ROM limit that only affects the MacOS....

Although I don't know for sure if there's something else limiting the
SE from using 128 megs of RAM, yes, the original limitation was at 14
megs.  The MacOS used to use 24-bit addressing, and a good bit of that
space was dedicated to devices, especially NuBus slots, leaving only
14 megs for RAM.  When System 7 came out, they made the change to
32-bit addressing, and with a little System patch from Connectix, even
old Macs can use the 32-bit addressing scheme.

Scott Kaplan
sfkaplan@cs.utexas.edu