A GameBoy emulator written in Java!
Do you want to make a GameBoy emulator? The folowing links may help... =P
General documentation
How to make a (GameBoy) emulator?
CPU instruction set
GameBoy CPU InstructionSet Sheet
GameBoy CPU (LR35902) instruction set
GameBoy CPU instructions reference
ZINT Z80 INTERPRETER (CPU instructions)
Just to make things clear..
Difference between JUMP and CALL instructions