Hey All,
I am now, on Ekhard's (did I spell that right? Sorry?) suggestion,
studying the dissassembled code of Kool-Aide Man to try and find a way to
write code that auto detects PAL or NTSC and executes apropriate code within
software so that players don't have to manually select their format in
future releases. Kool Aide Man on NTSC works fine but freaks out and
overlaps players on PAL causing contast collision. Here is my theory after
examinging the code. In it they write the same value with an STA into both
RESP0 and RESP1 one line after another like this
LDA #$20
...
...
...
STA RESP0
STA RESP1
I've never seen this in code before, but I'm new to this so someone throw in
2 cents. If the read of the TIA registers happens after the first STA but
before the second STA command there should be a gap of around 15 cycles
between their draw to the screen, right (or is 5 cycles)? Well, if that is
true then it should mean that the PAL system is reading the TIA registers at
a different time than the NTSC system would have. Meaning that it is told
to reset P0 and P1 to the same horizontal position at the same time and
thusly creating the problem were two items overlap at roughly the same spot
and cause constant collision. Is that right? Any opinions? I don't have a
PAL system to test anything on so I can't write and test any code, but does
this sound correct to anyone? Opinions welcomed.
Christopher Rydberg
solitaire0@xxxxxxxxxxx
afterlife.100megsfree4.com
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