RE: It's working!

> Now... on to to the bank switch mod...

I don't think you specified, but if you intend to directly
connect your register's output to the upper address lines
of your program store device, remember that once you write
the register, the next opcode will be fetched from the
PC's offset within *the new bank*.

Some creative opcode placement can work around this
(I don't think the 6502 does any prefetching).

A trick I've used to work around this issue is to copy
the bank selection code and jump into ram, then jump to
the ram, then jump back to rom after the bank switch,
so you don't pull the rug out from under yourself.

Hope this is of some use.

-Mark
 

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Received on Wed Apr 25 15:01:58 2001