Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!ucsd!rutgers!rochester!pt.cs.cmu.edu!IUS3.IUS.CS.CMU.EDU!ralphw
From: ralphw@IUS3.IUS.CS.CMU.EDU (Ralph Hyre)
Newsgroups: comp.unix.aux
Subject: A/UX MacOS co-existence
Message-ID: <1451@pt.cs.cmu.edu>
Date: 18 Apr 88 12:59:14 GMT
References: <232@voysys.UUCP> <1711@desint.UUCP> <8075@apple.Apple.Com> <8398@oberon.USC.EDU> <347@caldwr.caldwr.gov>
Sender: netnews@pt.cs.cmu.edu
Organization: Carnegie-Mellon University, CS/RI
Lines: 33
Keywords: Macintosh A/UX HFS
Summary: use virtual machine stuff in 68020

In article <347@caldwr.caldwr.gov> ack@caldwr.caldwr.gov (David Ackerman) writes:
>I saw a lot of potential in the version of A/UX I used. But potential doesn't
>develop by itself. A/UX should be to the Mac OS what the Roadrunnner is to DOS.
>If Apple doesn't understand what I mean, they should go play with a Roadrunner.
I saw a RoadRunner the other day, and I understand.  I don't work for Apple,
though, and I'm not a 680X0 hacker.
Ideally, you want to be able to run any 'reasonable' Mac application under
A/UX.  The good news is - theoretically you can!

The 68020 supports the idea of a virtual machines, you can run any
number of independent 680X0 programs in user mode, even if they
want to run in supervisor mode.  The 80386 has virtual 8086es,
so I imagine that the RoadRunner is somewhat limited in the type of 
Intel-based software it can run. (ie no '286 or '386 software). 

When you try to do something which requires supervisor priviledges,
you get a priviledge exception (or something like it), which the
code running in supervisor mode (A/UX) can deal with.  

I Imagine that you could even work out memory access problems by
setting up the PMMU to generate exceptions for accesses to certain
areas (like the screen). (You'd want them to use A/UX windows, whatever
those are.)

So, by redirecting and possibly recoding some toolbox calls, and adding some
code to the A/UX kernel - you can run even more Mac applications.  I've been 
thinking of doing this to the Sun-3 on my desk - wouldn't that be embarassing
for Apple, to have MacOS software running on a competitor's Unix box, while
A/UX doesn't even grok HFS.
-- 
					- Ralph W. Hyre, Jr.

Internet: ralphw@ius2.cs.cmu.edu    Phone:(412)268-{2847,3275} CMU-{BUGS,DARK}
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