[Coco] [Color Computer] Multi-Pak Question
lamune at doki-doki.net
Sat Jan 31 00:26:03 EST 2009
It's a little more complicated than that. Let's see if I can add to what
everyone already has said.
There is a cartridge I/O select line and a cartridge ROM select line at
the CoCo port. There is a register in the multi-pak (and the front panel
switch) that determine which slot gets those two signals. The I/O space
is from $FF40 to $FF5F.
If you have a cart that uses I/O space that's not in that range, for
instance, the RS232 pak, it doesn't matter what slot is selected or not-
that device will function, because it doesn't care about the cart I/O
select line from the CoCo
The multi-pak is designed such that it feeds all the unused "I/O" space-
probably from $FF40 to $FFBF. This is the reason there is a CoCo 3
update for the pak, because it will respond to the I/O space that the
GIME addresses are mapped to and cause unpredictable behavior.
As I think Phill pointed out, the CoCo Max pak lives at $FF90 and won't
work with a modified MPI- nor will it function on a CoCo3 for that
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