Message-Id: <m0ys7QH-000S3nC@inti.gov.ar>
Comments: Authenticated sender is <salvador AT natacha DOT inti DOT gov DOT ar>
From: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT gov DOT ar>
Organization: INTI
To: "Arthur" <arfa AT clara DOT net>, djgpp AT delorie DOT com
Date: Fri, 3 Jul 1998 12:13:35 +0000
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Subject: Re: 64k demo
In-reply-to: <010701bda68f$7a7ba6a0$e44e08c3@arthur>
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"Arthur" <arfa AT clara DOT net> wrote:

> >Sorry, you're wrong. The Intel 80x86 machines are 2's complement.
> >This means that -2 is 11111110. Shifted left this produces 11111100, or
> >-4.
> >SHL and SAL are the same bytecode on Intel 80x86.
> >CF <- register <- 0   (high bit is shifted into the CF (carry flag),
> >zero is shifted into the least significant bit)
> >
> >SHR and SAR are different bytecodes however.
> >SHR produces
> >0 -> register -> CF    (0 is shifted into high bit, low bit is shifted
> >into CF (carry flag))
> >whereas SAR produces
> >sign bit -> register -> CF   (the sign bit is replicated in the high
> >bit, low bit is shifted into CF (carry flag))
> 
> 
> Oh, for a decent processor. I'm sorely tempted to go back to my ST.
> 
> >> These are obviously different to arethmetic shifts.
> >Only on the Motorola (and similar) chips. Not on the Intel 80x86.
> 
> 
> You say "only." I know of no other processor other than the x86 (and
> compatibles) that have such an illogical and unfriendly instruction set.

That's because you don't know much about RISC processors.

SET 
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