Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!jarthur!wilkins
From: wilkins@jarthur.Claremont.EDU (Mark Wilkins)
Newsgroups: comp.sys.mac.misc
Subject: Re: MachTen for Macintosh (YAFI)
Message-ID: <9170@jarthur.Claremont.EDU>
Date: 17 Oct 90 15:18:43 GMT
References: <220350@<1990Oct16> <143400029@uxa.cso.uiuc.edu>
Organization: Harvey Mudd College, Claremont, CA 91711
Lines: 27

In article <143400029@uxa.cso.uiuc.edu> ml27192@uxa.cso.uiuc.edu writes:
>
>>  Note that the IIsi and IIci are not on the list?  That's because on those
>>machines applications DON'T run in supervisor mode.
>
>Where do you get this information? I thought the toolbox ran in supervisor
>mode, and that this also is related to programs being able to get system
>resources.


  Simple.  Whenever I break into MacsBug on my IIci the supervisor mode bit
is turned off unless I do it within a system call.

  The IIci was the first machine to have the MMU activated by default rather
than running in a mode which just passes address bits through.

  Anyway, there is a set of Mac IIci programming notes available from APDA
which confirm this.  Also, Apple has long been warning application
developers not to assume supervisor mode, and this is what caused some of
the IIci incompatibilities to start with.

-- Mark Wilkins
-- 
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