Xah Lee's Unixism

[SM Ryan]

"Karl A. Krueger" <kkrueger at example.edu> wrote:
# In comp.lang.lisp Pascal Bourguignon <spam at mouse-potato.com> wrote:
# > "John Thingstad" <john.thingstad at chello.no> writes:
# >> Note the Mac OS 10 / Darwin uses a unix kernel because of all the
# >> problems  with interoperabillity OS 9 had with talking to Windows and
# >> Unix boxes.
# > 
# > No that's not the reason. The reason is ONLY because of the lack of
# > virtual memory management (with separation of addressing spaces for
# > processes) in MacOS.
# 
# It was my impression that the Motorola 68000 CPU, upon which the
# original Macintosh was based, did not support memory management in
# hardware.  At least, that's usually given as the reason that portable
# Unix systems such as NetBSD will "never" run on the earlier 68k (or,
# for that matter, 8086 or 80286) chips.

It needed an extra chip until about the 68020. Mac system 7 had a form of
virtual memory; there are Linux and BSD versions that are advertised to
run on the 68020 or later.

MacOSX still has cruft from 1984 system 1, but now it's the outer layers
on top of the Unix kernel calls instead of Posix functions layered on
top of cruft.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
Raining down sulphur is like an endurance trial, man. Genocide is the
most exhausting activity one can engage in. Next to soccer.