Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!vu-vlsi!swatsun!jackiw
From: jackiw@cs.swarthmore.edu (Nick Jackiw)
Newsgroups: comp.sys.mac
Subject: Re: Exiting to finder on sysbomb
Message-ID: <3138@carthage.cs.swarthmore.edu>
Date: 28 Sep 89 14:58:25 GMT
References: <15778@dartvax.Dartmouth.EDU>
Reply-To: jackiw@carthage (Nick Jackiw)
Organization: Visual Geometry Project, Swarthmore College, PA
Lines: 29

In article <15778@dartvax.Dartmouth.EDU> xerox@eleazar.dartmouth.edu (James Osborne) writes:
> I know that when I had my SE, I could type G 409b24 in the monitor if
> I got a sysbomb and that would SOMETIMES exit me to the Finder so that I
> could restart properly.  Is there a similar address that will work on
> my SE/30?
> James.Osborne@mac.dartmouth.edu

This presumably executed the _ExitToShell subroutine in every Mac rom, which
should dispose of all of the memory allocated to your application (or the
one which is currently "switched in" if you're running multiFinder), and
reload the Finder.

Internally, Macs provide a way to access most of their built-in subroutines
(the famous Toolbox + OS Routines) that remains constant despite revisions
and updates to the ROMs (which entail moving the location, e. g. 409b24, of
subroutines).  On *any* Mac, entering 'SM 0 A9F4' will set memory location
$00 to $A9F4, the magic trap code to invoke the _ExitToShell subroutine.
Then you just type "G 0" to begin executing at that memory location and
you should, provided the crash was not *too* fatal, wind up back in the
Finder.

Sorry to be so wordy.  Don't know what level of detail you wanted.


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