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From: Lawson.English@p88.f15.n300.z1.fidonet.org (Lawson English)
Newsgroups: comp.sys.mac.programmer
Subject: Re: System 7.0/Supervisor Mode ?
Message-ID: <10972.282FE0AB@stjhmc.fidonet.org>
Date: 13 May 91 04:55:33 GMT
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Brian Kendig writes in a message to All

BK> How difficult a modification would it be to have my SE use user 
BK> mode, too? Is this a matter of a simple INIT that would just 
BK> toss my machine into user mode without worrying about VM, or 
BK> am I talking about something that would require a major rewrite 
BK> of the operating system here?

Speaking sans true knowledge (as is my wont), I'd guess that "32-bit clean"
is the telling factor as to whether supervisor or user mode is to be used-if
an application is 32-bit clean, then the OS developers probably assumed that
it would be following the rest of Apple compatibility guidelines.

As to whether your SE could use it, hmmmm... I doubt it, as there would be no
easy way to determine when an OS call needed supervisor mode, and when it could
use supervisor mode. Maybe patching all traps..., but what if someone does their
own patching? And what about VBL tasks, etc? (and what about Naomi?)

Lawson
 

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