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From: rdclark@Apple.COM (Richard Clark)
Newsgroups: comp.sys.mac.programmer
Subject: Re: A-Trap length
Message-ID: <40137@apple.Apple.COM>
Date: 8 Apr 90 23:27:33 GMT
References: <1645.2610e886@vaxa.uwa.oz> <4598@daffy.cs.wisc.edu>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 24

In article <4598@daffy.cs.wisc.edu> upl@gumby.cs.wisc.edu (Undergrad Projects Lab) writes:
:I'm writing a little program for myself and I need to copy some of the ROM
:traps to RAM. 

  Don't try it. Assuming that you get the "correct" length (BTW -- the traps
in ROM are not necesarily sorted according to their trap numbers), you still
have to deal with the following questions: 1) Did I actually get the trap,
or somebody's patch to it?, and 2) What do I do about the PC-relative jumps
encoded in the trap codes themselves? (Surprise! There are some utility
routines in ROM which get called directly.)
 
  If you can describe *why* you want to get the code out of ROM, we all can
probably find a better way to do what you want.
 
...Richard



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