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hey guys, works been slow lately so ive been working on a hack, or to be more specific, a hack of a hack. the original hack was based on motocross, but the bike sprites had been replaced pod racers. its on JDD (http://jims_digital_domain.tripod.com/dwnloads.htm) if you want to have a look. Im taking it a step further by modifying all the other sprites (done) and changing the background (also done), but I also want to change the color of the sprites and background. witch is where im at a loss, ive made mods to games that use sprites in the past shure, (EX: chris sawyers locomotion) but in those games the sprite contained the colors used in it. on the Atari however, it seems the colors must be contained somewhere in the games code, and sense both the sprites and and all other code are in binary im having a difficult time finding what determines the color of the sprites. are there common locations in the bin to look for the colors, or are there any tools that can help me find them? I would appreciate any help, thank you.

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The player's sprite color table is at addresses $9887-$989B in the original game...but it looks like the zero values at the top are being shared with a bitmap. You'd need to disassemble the game and unshare those lines if you wanted the top of the sprite to be something other than black.

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BTW there are no "common" areas to search for game colors among game programs...unless one is an obvious hack of another that you know the locations of. But the 2600 does not use the rightmost bit for color data (so in color data tables, you'll often see that bit is zero).

 

Searching for COLUP0 and COLUP1 in this game, for example, is only part of the solution...because the data tables are being read from via LDA(indirect),Y. In other words, the address held in ram memory specified by the address between the ()'s PLUS the current value of the Y register is where it is read from. Stella's debugger is really valuable here, since you can right-click a point anywhere on the screenshot, choose "fill to scanline", and the running game's "display kernel" will stop at that point...where you can read through the program instructions and see the contents of ram memory in their corresponding windows.

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