The usual place to start to start an emulator is the CHIP-8 (https://en.wikipedia.org/wiki/CHIP-8 https://en.wikipedia.org/wiki/CHIP-8), because it's a very eas

The usual place to start to start an emulator is the CHIP-8 (https://en.wikipedia.org/wiki/CHIP-8 https://en.wikipedia.org/wiki/CHIP-8), because it's a very easy platform that don't have a lot of the "complicated" stuff that's in more complex hardware. The overall logic is very simple (read a program into ram, read an opcode from the starting location, do whatever that opcode is supposed to do, go to the next opcode... rinse and repeat) and you can find tons of tutorial online (I liked this one: http://www.multigesture.net/articles/how-to-write-an-emulator-chip-8-interpreter/ http://www.multigesture.net/articles/how-to-write-an-emulato...) It should set your mind on the fact that writing a simple emulator is just doing a fetch/decode/execute (https://en.wikipedia.org/wiki/Instruction_cycle https://en.wikipedia.org/wiki/Instruction_cycle) on some code. For the documentation, I've found that EmuTalk (www.emutalk.net/forums/30-Emulator-Programming) has tons of interesting links.