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From: andrew@jhereg.osa.com (Andrew C. Esh)
Newsgroups: comp.sys.mac.programmer
Subject: Re: What is "Mr. Bus Error"?
Message-ID: <1991Mar28.235742.16765@jhereg.osa.com>
Date: 28 Mar 91 23:57:42 GMT
References: <1991Mar24.000535.15131@usenet.ins.cwru.edu>
Organization: Open Systems Architects, Inc., Mpls, MN
Lines: 26

In article <1991Mar24.000535.15131@usenet.ins.cwru.edu> drz@po.CWRU.Edu (David R. Zinkin) writes:
>
>Could someone please tell me what the program "Mr. Bus Error" is,
>and what it's supposed to do?  After hearing the name, I just had
>to ask.
>
>Thanks,
> -- Dave
>
>-- 
>David Zinkin -- Case Western Reserve University (Student) and
>      Rochester General Hospital Radiology Dept. (Consultant)
>
>"If we dream it, it can be done." -- Bob Anastas, founder of SADD

Mr. Bus Error puts the hex number "F0F0F1" in location 0 of the Mac's
memory every so often. If a nil pointer is referenced as if it is a valid
pointer, the odd number will immediately cause a Bus Error. Thus you stand
a zero chance of successfully using a nil pointer, instead of a fifty-fifty
chance that the pointer will appear valid, and allow you program continue
its trek into the deep weeds unnoticed.
-- 
Andrew C. Esh			andrew@osa.com
Open Systems Architects, Inc.	
Minneapolis, MN 55416-1528	So much System,
(612) 525-0000			so little CPU time...