>PLA might certainly be preferable over LDA, though. If for some reason you
>need to make, say, 12 TIA writes from a variable place in ROM, copying
>those 12 bytes into RAM offscreen and looping PLA/STA in the kernel is
>faster than doing LDA indirect indexed/STA.
Yes, true.
But If I was that desperate, I'd try very hard to use self-modifying code in
zero-page. That way you'd come down to just 5 cycles for each load/store
rather than 11 for indexed indirect or 7 for PLA/STA. In the 12 byte
example, you'd need a scratchpad space of 48 bytes - expensive, though :)
Nonetheless, you offset it by the 12 bytes of stack you're proposing, and
its penalty is 36 bytes.
Time to dig out that old multiple variable area overlays assembler, mmh?
Cheers
A
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