🚀 go-pugleaf

in article <89091323592891@masnet.uucp>, dean.gaudet@canremote.uucp (DEAN GAUDET) says:

> Since the A2620 allows you to use the 68000 through a startup selection,
> wouldn't it be possible to use BOTH processors?  

While the A2000 design would permit the use of both CPUs simultaneously, the
A2620 itself doesn't.  The 68020 is held in reset until the A2620 logic takes
the bus from the 68000.  And to get the 68000 back, the 68020 is forced back
into reset.  Why?  It made the design _so_ much easier, especially considering
that the original A2620 design wasn't intending to let the 68000 back on at
all.  Why?  I dunno, I didn't get on the A2620 until after that decision had
been made, and I thought, "hey, that's stupid, we should be able to kick the
68000 back in if necessary", and found the simplest way to do that, given the
existing A2620 design.

> ie:  Use the 68020 as an amiga 2500, and make the 68000 think it's just a 
> plain 2000.

That would be a major software undertaking.  If it would work at all.  More
likely, you'd use the 68000 as a device under the 68020's control; maybe
have the 68000 run a custom filesystem and other I/O, or similar.  It would
still take lots of new software, but at that level could at least break
the question of "what does the 68000 do" into bite-sized pieces.

> You could use the 68885 (MMU) to remap AbsExecBase for the 68020.

             that's 68851

And yup, it could remap AbsExecBase.  

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