Article View: comp.sys.mac
Article #10236Re: ShortCut vs. Boomerang: Opinions?
From: Justin Vallon
Date: Mon, 22 Jan 1990 22:48
Date: Mon, 22 Jan 1990 22:48
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2169 bytes
In article <44959@improper.coherent.com>, dplatt@coherent.com (Dave
Platt) writes:
> [Comments about Boomerang]
>
> Back around 2.0B5 or so, I installed the Mr. Bus Error INIT, which
> repeatedly stomps location 0 with an odd doubleword... this rapidly
> detects code which is dereferencing an empty-but-not-null handle (very
> much a no-no). Boomerang immediately began suffering from bus errors,
> aborting the current application.
(I assume that Mr. Bus Error is something like a VBL task that writes
to location $0 every interrupt). I have two questions.
(a) I'm using Virtual. There is no part of the address space (that is,
when you've set 14Mb VM space) that will cause a bus error (at least,
I believe). The memory map of my Mac II w/14Mb VM:
(Addresses are VM addresses, not physical addresses)
$000000-$7FFFFF Ram (8 Mb)
$800000-$83FFFF Rom (256K)
$840000-$EFFFFF Ram (768K + 6 Mb)
$F00000-$FFFFFF Video card
So, unless the video card causes a bus error (I have no idea about this),
then there is no bus-error address.
BTW, what's the point of being odd? Isn't a bus error enough? Anyway,
68020's and beyond don't generate address errors, right?
(b) Where can I get this. I suppose that it's a few minutes of code, but
I'm lazy.
> --
> Dave Platt VOICE: (415) 493-8805
> UUCP: ...!{ames,apple,uunet}!coherent!dplatt DOMAIN: dplatt@coherent.com
> INTERNET: coherent!dplatt@ames.arpa, ...@uunet.uu.net
> USNAIL: Coherent Thought Inc. 3350 West Bayshore #205 Palo Alto CA 94303
-Justin
vallon@sbcs.sunysb.edu
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!zaphod.mps.ohio-state.edu!sunybcs!sbcs!sbmiclr!vallon From: vallon@sbmiclr.cs.sunysb.edu (Justin Vallon) Newsgroups: comp.sys.mac Subject: Re: ShortCut vs. Boomerang: Opinions? Keywords: ShortCut Aladdin Boomerang Message-ID: <4520@sbcs.sunysb.edu> Date: 22 Jan 90 22:48:52 GMT References: <44959@improper.coherent.com> <13977@fluke.COM> <2940@murtoa.cs.mu.oz.au> Sender: news@sbcs.sunysb.edu Reply-To: vallon@sbmiclr.cs.sunysb.edu (Justin Vallon) Lines: 40