[Segher] has reverse engineered the hardware and command set for the NES CIC chips. These chips make up the security hardware that validates a cartridge to make sure it has been licensed by Nintendo. Only after authentication will the console’s CIC chip stop reseting the hardware at 1 Hz. The was no hardware information available for these chips (go figure) so [Segher] had to do some sleuthing with the tools at hand which include some rom dumps from the chip pairs. He was nice enough to share his findings with us. We’re betting they’re not of much use to you but we found it an interesting read.

[Thank ppcasm]

[Photo credit: Breaking Eggs and Making Omelets]