Michael J. Mahon wrote:
Thanks. I was indeed thinking that every store instruction causes two
accesses. If not, the solution I gave above seems to be ideal,
provided you use an absolute address, not some expression that has to
be calculated at runtime (which will compile into an y-indexed
indirect store).
...which is exactly the problem with slot-relative addresses.
It is. But then, the only real "toggle" switches, where the same address
switches both ways, are the speaker and cassette outputs, I think. Or
are there any more?
(I removed the non-apple groups from this one)