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From: mwm@ea.UUCP
Newsgroups: net.micro.68k
Subject: Re: 68020 production samples announced - (nf)
Message-ID: <7400004@ea.UUCP>
Date: Wed, 18-Jul-84 17:29:00 EDT
Article-I.D.: ea.7400004
Posted: Wed Jul 18 17:29:00 1984
Date-Received: Sat, 21-Jul-84 04:32:19 EDT
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Nf-ID: #R:sun:-154300:ea:7400004:000:812
Nf-From: ea!mwm    Jul 18 16:29:00 1984

#R:sun:-154300:ea:7400004:000:812
ea!mwm    Jul 18 16:29:00 1984

/***** ea:net.micro.68k / utzoo!henry /  2:02 pm  Jul 15, 1984 */
And as far as warts go, has Motorola
fixed that awful botch of having to save microcode state when the cpu
gets a page fault?
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry
/* ---------- */

That's not a wart, that's a *feature*. They call it "instruction
continuation," as opposed to the more conventional "instruction restart."
They designed it that way.

It's supposed to be a performance enhancement - you don't have to roll the
instruction back [for things like MOVE.W (A0)+,(A1)+], and you don't have
to redo the rolled-back part of the instruction when you continue the
faulted process.  Whether or not it works in practice, or the pain of
dealing with it is worth the gain, I don't know

	<mike