nraygun

Oh, I see, I didn't realize the cartridge had a whole other processor in it. Found this, "DPC+ is an extension of the original DPC chip that was developed by Activision and included in the Pitfall 2 game released in 1982. It basically allows you to update graphics faster and much easier, and also includes more ROM, RAM and better sound. The DPC is actually implemented using a 70mhz ARM processor, so in addition to its features, it also allows you to write game logic in C which is then executed by the ARM. All interaction with the TIA still needs to be done in 6502 assembler." So it's really like a whole new system given the additional ARM CPU. Sort of.

I had to join this forum specifically to congratulate the team on Mappy for a job well done! The port is absolutely stunning and an impressive achievement given the hardware. Wonder if Atari could have made an Atari 2600+ with a built-in DPC chip back in the day. Seems like it would have given the NES a run for its money. Hat's off to the developers of Mappy!