[stella] The Kool-Aide Solution...

Subject: [stella] The Kool-Aide Solution...
From: "Christopher Rydberg" <solitaire0@xxxxxxxxxxx>
Date: Mon, 30 Jul 2001 08:55:49 +0000
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

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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