Understood.
I was actually doing some reading and saw where several authors have revised code withing the ROM data to allow certain games to save high scores. Being Im an old techie from way back, and have dabbled in plenty of coding for chipsets, I wanted to have a look at the code on the eeprom. Using a generic eeprom editor I was able to open and look at the data on chip 1D (the chip that holds the info for save game stuff) and make a simple compare of an altered chip vs a stock chip. I can see where the date was changed to allow the "save game" info, unfortunately without the opcode list or instruction set, I can not decypher the code.
A snipit of code that looks like this
$000060,06 20 AD 07 20 A0 74 AD 07 20 99 00 66 C8 D0 F7
$000070,A9 02 8D 16 40 A0 05 B9 BA 66 99 D7 07 88 10 F7
$000080,20 74 92 AD 78 07 09 80 20 A5 91 4C 8B 80 01 A5
could easily be interpreted with the correct opcode set.
06 20 AD could mean branch to address 20AD or it could mean a hundred different things.
LOL...long story short, I was just trying to find an instruction set for that particular Eeprom so I could poke a round a little.
Thanks,