Article View: comp.sys.mac
Article #14639Re: Mouse Anti-Freeze routine needed.
From: roman
Date: Sat, 14 Feb 1987 16:14
Date: Sat, 14 Feb 1987 16:14
16 lines
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1492 bytes
In article <678@bgsuvax.UUCP> denbeste@bgsuvax.UUCP (William C. DenBesten) writes: > [...] I have found a way to freeze my mouse pointer.... >I suspect that the problem involves the vertical retrace interupt becoming >disabled, but I haven't yet delved into that chapter of Inside Macintosh. I did a little delving in volume III. The mouse interrupt is (kludge!) coming in on the SCC. The "DCD" signals of channels A and B are used. What is probably happening is that stray writes are wiping out the control registers of the SCC. Another possibility is that the processor priority is being set to mask out this interrupt. This seems less likely because this would involve a stack frame mixup and would probably send execution off to never-never land. So what some wizard needs to do is find out how to get the SCC's state restored to something which will re-enable this interrupt.
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arc1-ca.pugleaf.net!utzoo!watmath!clyde!rutgers!mit-eddie!genrad!decvax!tektronix!uw-beaver!tikal!sigma!romanReferences:
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!rutgers!mit-eddie!genrad!decvax!tektronix!uw-beaver!tikal!sigma!roman From: roman@sigma.UUCP Newsgroups: comp.sys.mac Subject: Re: Mouse Anti-Freeze routine needed. Message-ID: <1064@sigma.UUCP> Date: Sat, 14-Feb-87 11:14:00 EST Article-I.D.: sigma.1064 Posted: Sat Feb 14 11:14:00 1987 Date-Received: Sun, 15-Feb-87 08:12:22 EST References: <678@bgsuvax.UUCP> Reply-To: roman@sigma.UUCP (Bill Roman) Organization: Summation, Inc., Kirkland, WA Lines: 16 Summary: Try re-initializing the SCC