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From: csbrod@medusa.informatik.uni-erlangen.de (Claus Brod )
Newsgroups: comp.sys.amiga
Subject: Re: motorola/intel
Keywords: Instruction set, memory-mapped I/O
Message-ID: <3121@medusa.informatik.uni-erlangen.de>
Date: 20 Sep 90 12:27:18 GMT
References: <30140@nigel.ee.udel.edu> <14427@cbmvax.commodore.com> <566@DIALix.UUCP>
Organization: CSD, University of Erlangen, W-Germany
Lines: 22

bernie@DIALix.UUCP (Bernd Felsche) writes:

>But, but what about the 680x0's MOVEP instruction?  It exists to
>support the older 6800 chips.  And presumably consumes some
>instruction decoding.
MOVEP not only supports 6800 chips but several other 8-bit peripheral
chips. It's a more universal concept.#

>I know that "nobody" uses it, but it is there.  Or wouldn't you
>class it as an I/O instruction?  Agreed, it is not I/O mapped. but
>it *is* a special I/O instruction.
If "nobody" is me, nobody uses it. I'm mainly programming STs, and the
MOVEP instruction sometimes serves me well to do some kind of interleaved
memory transfer or parameter shuffling. It is not at all worthless on
my machine, and I'd think there are many applications for it on Amigas, too.


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Claus Brod, Am Felsenkeller 2,			Things. Take. Time.
D-8772 Marktheidenfeld, West Germany		(Piet Hein)
csbrod@medusa.informatik.uni-erlangen.de
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