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From: hardy@sdccsu3.UUCP
Newsgroups: net.unix
Subject: Re: Motorola Unix Port
Message-ID: <1819@sdccsu3.UUCP>
Date: Wed, 9-May-84 14:29:41 EDT
Article-I.D.: sdccsu3.1819
Posted: Wed May  9 14:29:41 1984
Date-Received: Sat, 12-May-84 08:38:56 EDT
Organization: U.C. San Diego, Computer Center
Lines: 23

The Motorola port of Unix System V as currently shipped by Motorola only
supports the EXORMACS MMU, which is a base and bounds design, and does not
map in system state.  Because of the way Motorola did the MMU code, it takes
well over four milliseconds to effect a task switch, of which two milliseconds
is at spl7.  If you are planning on accepting input on a serial line at 9600
baud, prepare to drop characters.

Also, Motorola has yet to release the source for the C Compiler becuase
AT&T is trying to get more money from Motorola and Motorola's Customers.

Supposedly, Motorola has the MC68451 Code working, but from the embryonic
code embedded in the released System V sources, it will only work with the
MC68010, and not the MC68000.  This is because they disable all the
segmentation registers at task start up and only load registers when they
get a bus error.

I suspect that this does not make AT&T totally unhappy, since many 68000
machines directly compete with their 3B series.

Michael Christensen
Unix System V Project Manager
Alcyon Corporation