Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!uwvax!oddjob!gargoyle!ihnp4!chinet!dag From: dag@chinet.UUCP (Daniel A. Glasser) Newsgroups: comp.sys.atari.st Subject: Re: strange bug? Message-ID: <1914@chinet.UUCP> Date: Thu, 26-Nov-87 10:48:24 EST Article-I.D.: chinet.1914 Posted: Thu Nov 26 10:48:24 1987 Date-Received: Sun, 29-Nov-87 23:19:41 EST References: <21951@ucbvax.BERKELEY.EDU> Reply-To: dag@chinet.UUCP (Daniel A. Glasser) Organization: Chinet - Public Access Unix Lines: 17 Keywords: m68000 excpetion handling Summary: Not so strange -- Read up on 68000 exception handling Your posting indicates that you are changing a machine register in an exception handler without restoring it. This is a no-no in systems programming, at least on the 68000. You don't know what's going on when most hardware exceptions take place, and when the exception handler returns, whatever it was that was taking place tries to continue. If it needs the data in that address register that you clobbered, the system is likely to start doing very odd things. I suggest reading up on exception handling in a 68000 manual (though the idea is the same as most register machines). -- Daniel A. Glasser ...!ihnp4!chinet!dag ...!ihnp4!mwc!dag ...!ihnp4!mwc!gorgon!dag One of those things that goes "BUMP!!! (ouch!)" in the night.