Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site rlgvax.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!wjh12!harvard!seismo!rlgvax!guy
From: guy@rlgvax.UUCP (Guy Harris)
Newsgroups: net.micro.68k
Subject: Re: detecting processor type (68000/68010/etc) in software?
Message-ID: <217@rlgvax.UUCP>
Date: Fri, 26-Oct-84 01:26:27 EDT
Article-I.D.: rlgvax.217
Posted: Fri Oct 26 01:26:27 1984
Date-Received: Sat, 27-Oct-84 04:29:44 EDT
References: <368@foros1.UUCP> <1753@sun.uucp>
Organization: CCI Office Systems Group, Reston, VA
Lines: 19

> I know of no way for user code to distinguish a 68000 from a 68008
> or 68010 or 68012.  This is deliberate, like on a 360 or 370, since
> it means you CAN'T write a program that won't transport from one
> to the other.

Why won't trying to execute an RTD instruction separate the 68010s from
the 68000/68008s?

> What would your library routine do differently if it knew it was
> on a 68000 versus 68010?  There really isn't that much difference.

I seem to remember some discussion a while ago on the fastest way to do
a block move, which implied that the MOVE.L/DBcc pair was faster on the
68010, but not on the 68000.  (Not that the library routine should burn
up a goodly number of the cycles saved by trying to do an RTD and catching
the illegal instruction trap...)

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy