Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!brutus.cs.uiuc.edu!ginosko!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Amiga 3000 rumors
Message-ID: <7905@cbmvax.UUCP>
Date: 14 Sep 89 13:31:24 GMT
References: <1740@convex.UUCP>
Organization: Commodore Technology, West Chester, PA
Lines: 31

in article <1740@convex.UUCP>, swarren@eugene.uucp (Steve Warren) says:
> Keywords: Bed, A3000, doing it "right" this time.

> In article <4686@shlump.nac.dec.com> balzer@frambo.enet.dec.com (Christian Balzer) writes:

>>designers have learned this lesson. A really nice thing would be a 68000
>>as fallback CPU on the motherboard. Whilst giving utmost compatibility with
>>all the "standard" Amigas, this feature could be implemented at very low
>>costs...

> The motive being downward compatibility with the 68000 equipped Amigas.
> But is that (financially) possible with a 32 bit custom chip set?  

It would be expensive to adapt a 68000 to an inherently 32 bit bus.  And not
really necessary. ALL Amiga compatible software will run on any 680x0 CPU
available to date (programs that require something that's not there, such as
an FPU or MMU should exit gracefully with a warning message; any Software
Error action constitutes a bug here too).  If a program crashes due to the
CPU it's running on, that's a bug in the program, plain and simple.  Don't let
developers snooker you on this one -- most of the rules for general 680x0 
compatibility were available in the V28 ROM Kernel Manual (July 1985), well 
before AmigaOS 1.0 was released.  An extensive paper on this was presented a 
year and a half ago at the Developer's Conference in Washington D.C.  AND, to 
top it all off, there's been a 68020 machine with a 68000 fallback, the A2500,
available since the beginning of the year.

> --Steve
-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
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