[Coco] Super Cartridge

john dumas JohnDumas at austin.rr.com
Wed Jan 16 16:46:44 EST 2013


On 1/16/2013 3:16 PM, Luis Antoniosi (CoCoDemus) wrote:
> I/O ports are at FF00 - FFFF.
>
> A bank switching register ? Pretty much like the superIDE banks ?
I have never seen a 32k coco cart, but bank switching sounds
like the most likely way to "see" 32K thru a smaller address space hole...

Bank switching ROM programs get interesting. If you have
some scratch RAM, you can copy some small code there
to switch banks while you "are somewhere else".
Without RAM, you essentially have to saw off the limb
you are sitting on. Best saw off the limb correctly and
be fast on your feet to jump elsewhere!!!
(Or BRANCH if you can stand the pun.)

In the Day, we saw quite a bit of very creative ways to
stuff more code in a very limited address space.
Hardware to detect a read of a certain address and thus
change an address bit was not uncommon - think SAM
chip............

cheers,
johnd



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