Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!bbn!apple!AppleLink.Apple.Com!Marriott1
From: Marriott1@AppleLink.Apple.Com (Greggy)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Problem with LSP glue for SetClikLoop
Message-ID: <1524@internal.Apple.COM>
Date: 25 Apr 89 02:30:42 GMT
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc.
Lines: 21
References:<13147@dartvax.Dartmouth.EDU> <13148@dartvax.Dartmouth.EDU> <1681@husc6.harvard.edu> <13197@dartvax.Dartmouth.EDU>

In article <13197@dartvax.Dartmouth.EDU> matthews@eleazar.dartmouth.edu 
(Jim Matthews) writes:
> This isn't bulletproof.  Unlike most call-back routines, click loops
> have to preserve D2 and set D0 to a non-zero value at exit.  Hence the

This isn't quite true, although that's what IM v4 says.  The list manager 
code branches based on the state of the zero flag when the clikproc 
returns.  This means that the very last action the clikproc takes must 
clear the zero flag.  Setting D0 to a non-zero value works, but only if no 
other instructions mess with the zero flag before returning. (I spent many 
long hours tracking this down!)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Greg Marriott               +                      AppleLink: Marriott1 +
+ Just Some Guy               +                                           +
+ "My phone is always busy"   +   Internet: Marriott1@AppleLink.Apple.Com +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Just in case disclaimers mean anything at all:                          +
+    What I say comes from my own twisted perception of the world         +
+    and does not represent the policy or opinion of Apple Computer, Inc. +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++