This is an interesting, simple, and approachable explanation of how the Game Genie affects NES game code to change the behavior of the game with seemingly little context.
This is an interesting, simple, and approachable explanation of how the Game Genie affects NES game code to change the behavior of the game with seemingly little context.
I never had a Game Genie / GameShark as a kid but this is still a great overview of how the NES worked. I’d be super interested to read a more in depth article about the NES/SNES hardware if anyone knows of one.
This is an interesting overview of NES emulation and how it relates to the hardware: http://arstechnica.com/gaming/2011/08/accuracy-takes-power-one-mans-3ghz-quest-to-build-a-perfect-snes-emulator/
You could start with emulators people are writing. Brit Butler has been working on a 6502 emulator in Common Lisp, and has plenty of notes.