Re: Commodore 8296GD

From: Rhialto <rhialto_at_falu.nl>
Date: Sun, 30 Sep 2012 23:51:26 +0200
Message-ID: <20120930215126.GC9464@falu.nl>
On Sun 30 Sep 2012 at 10:05:55 -0700, Steve Gray wrote:
> I got some high-res pictures of this board from someone on forum64.de and I was hoping to reverse engineer this board as part of my "UltraPET" project (http://www.6502.org/users/sjgray/projects/ultrapet/index.html). I mention this board on my page.

VICE currently doesn't allow SuperPET and 8x96 memory expansions at the
same time. My first impression about that was that that would probably
be because the expansion connector is incompatible between 8032 and 8296
machines, and/or you can't connect 2 boards to that connector at once.
But the SuperPET board(s) don't connect via that connector, so that is a
moot point.

I didn't try it, but if the restriction were simply removed from VICE
with no other changes, I expect that the 8x96 memory would override the
SuperPET memory. I.e. if you enable one of the 8x96 expansion banks in
the $8000-$C000 range, you would no longer have access to the SuperPET
memory at $9000-$A000.

In reality, I'd expect the SuperPET memory to override though, since it
is "closer" to the CPU (the CPU is moved to the expansion board).

I'd think that the former way would be more useful, since keeping the
SuperPET memory block visible at all times would make it impossible to
access 2 x 4KB of 8x96 memory (4 KB in each of 2 banks).

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert  -- There's no point being grown-up if you 
\X/ rhialto/at/xs4all.nl    -- can't be childish sometimes. -The 4th Doctor

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Received on 2012-09-30 22:00:09

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