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From: rap@rap.ardent.com (Rob Peck)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Official Warnings...
Message-ID: <5881@ardent.UUCP>
Date: 18 Apr 89 00:29:16 GMT
References: <3082@haven.umd.edu>
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Reply-To: rap@rap.ardent.com (Rob Peck)
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Organization: Ardent Computer Corp., Sunnyvale, CA
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The poster referred to a warning from CATS not to use the TAS instruction.
As I remember, TAS is an instruction during which the 68000 believes
that it has the bus for the entire instruction execution time, and
effectively runs what it believes to be a Read/Modify/Write cycle.

But the custom chips don't take too nicely to this kind of activity
and can take away the bus before the instruction can be completed.
I don't know what effect that has on the instruction or the processor,
but it can, at the very least, make the instruction suspect.

Rob Peck