jindroush Posted March 11, 2003 Share Posted March 11, 2003 Hi, this chip is embedded in a cartridge I don't want to open. I know it's a math chip, has 4 registers: Input: 0,1,2 are for input, 3 is command. Output: 1,2 are output, 3 is status. I know that command 2 is multiplication of reg0 and reg2, result is stored in reg1 (hi), reg2 (lo). Status is probably 0 if ok, 1 if error. I also know that there is command 1, but I can't decode it's behaviour, it doesn't look like division... Does this ring a bell? Cartridge was produced in 1984. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 11, 2003 Share Posted March 11, 2003 What is the cartridge ? Quote Link to comment Share on other sites More sharing options...
Thomas Jentzsch Posted March 12, 2003 Share Posted March 12, 2003 Maybe you could give us some examples for command 1? Quote Link to comment Share on other sites More sharing options...
jindroush Posted March 12, 2003 Author Share Posted March 12, 2003 I finally solved that, stupid me! So command 2 is reg2 * reg0 -> reg1 (hi), reg2 (lo), multiplication Command 1 is reg1 * 256 + reg2 / reg0 -> reg1 (remainder), reg2 (result), division. If there's division error (overflow, div by 0), reg3 is set to 1, otherwise 0. Maybe the error does also set other registers, but I didn't care. I emulated the behavior and the game works fine. Cartridge is called SuperCharger, was produced by MPP/Supra. Game is loaded from disk and is called Assault Force. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 13, 2003 Share Posted March 13, 2003 Wow, I haven't seen this peticular cart before, would you mind posting a picture of it ? I presume it is for the Atari 2600, yes ? Quote Link to comment Share on other sites More sharing options...
+Mitch Posted March 13, 2003 Share Posted March 13, 2003 It's for the Atari 8bit computers. Mitch Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted March 13, 2003 Share Posted March 13, 2003 It's for the Atari 8bit computers. Mitch Ahh, nevermind then, thanks Mitch. Quote Link to comment Share on other sites More sharing options...
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