Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!bpa!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: AMIGA Fading?
Message-ID: <8695@cbmvax.UUCP>
Date: 23 Nov 89 05:14:38 GMT
References: <650@mts.ucs.UAlberta.CA>
Organization: Commodore Technology, West Chester, PA
Lines: 40

in article <650@mts.ucs.UAlberta.CA>, userPUB1@mts.ucs.UAlberta.CA (UACS Publicity Director) says:

> Commodore's current solution to this (on the 2000 and up) is

That's actually 2500, or in fall-of-89-speak, 2500/20 and 2500/30.

> When you reboot, hold down both mouse buttons, and you will be 
> presented with a menu asking you whether you want to work with 
> AmigaDOS running on the 68000 or 68020, or if you want AmigaUX

It's a nice feature, for sure, but realize that the reason you 
have it is that [a] A2000 based machines like either A2500 model
already have a 68000 in place, and [b] it was a real easy thing
to design into the A2620 and A2630 (basically for free).  I put
that feature in mainly to help out developers -- you can have
just one machine, and still test out your software on a 68000 
machine without taking apart your '020/'030 machine.  A side 
effect of this is that software that breaks on the '020/'030 can
still be run on the A2500.  But don't anyone expect that to last!
We don't support software that's 68000 specific -- all software
should run on any 680x0 processor if possible.  If you write
68020/30 specific code (for direct FPU calls or something), that's
OK, but you should check for the CPU type at the program's 
start, and exit gracefully on a 68000, 68010, or a machine 
with no FPU.  The A2500 does make a good transition machine; it
gives developers with buggy software a little extra time to fix
it.  But you can bet that future machines won't have a 68000 to
run this old stuff on; that would drastically cripple a full
high speed 32 bit machine.

Dropping back to the mode of your last CPU is for Intel machines.
Motorola processors did it right, with just a little bit of care
on the part of the programmer.

> -= Scott =-

-- 
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: hazy     BIX: hazy
                    Too much of everything is just enough