A system with less custom chips would probably be a cleaner target to emulate.

An Apple II is one of the simplest systems (no LSI except for the 6502 CPU) for which vast amounts of (easily available) games were written.

Emulators for an Apple II can be on the order of 10K lines of C code, possibly slightly less.

A system with the least amount of custom chips would probably be a cleaner target to emulate.

An Apple II is one of the simplest systems (no LSI except for the 6502 CPU) for which vast amounts of (easily available) games were written.

There have also been tons of (vintage) books and articles published on the system architecture of the Apple II and the 6502 CPU. Thus the system has been fairly well documented by multiple (cite-able) sources.

Emulators for an Apple II can be on the order of 10K lines of C code, possibly slightly less, which might fit within your course time frame.