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From: larryh@tekcbi.UUCP (Larry Hutchinson)
Newsgroups: net.micro.mac
Subject: 68020+68881 in a mac?
Message-ID: <441@tekcbi.UUCP>
Date: Wed, 18-Dec-85 11:18:23 EST
Article-I.D.: tekcbi.441
Posted: Wed Dec 18 11:18:23 1985
Date-Received: Fri, 20-Dec-85 04:54:11 EST
Organization: Tektronix, Beaverton OR
Lines: 31


For the brave & rich hacker:

	I just received a data sheet on a mezzanine board containing a 68020
	and a 68881 that plugs into a normal 68000's 64 pin dip socket.
	The board is 2.5" by 3.2" by 0.3".  The price was not given but I
	would guess it is steep (>$1000).  Those who are interested should
	contact:
		IO Inc.
		2430 N. Huachuca Dr.
		Tucson, Arizona 85745
		(602) 792-0969
	
	Please note the following possible problems:
		1)  The mac's 68000 is soldered in. No socket.
		2)  The exception stacking is different for the 68020.  Mac
		    software may break.
		3)  The main advantage that the 68020 brings is the higher
		    clock rate (up to 20MHz) and the 32 bit bus.  Neither
		    is applicable.  (But I would love to have the 68881!)
		4)  It sucks 400ma more than the 68000.  One would hope this
		    is negligible.
		5)  There may be others.

	Also, I suspect that there are many companies making similar products
	and that the price may become reasonable in the comming year.  If
	anyone tries this (and I doubt it!), let the net know.


Larry Hutchinson, Tektronix, Inc. PO Box 500, MS 02-305, Beaverton, OR 97077
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