Yep, it does. Suppose a contains %00111010, hl contains $6523 and the byte at $6523 is %10010111 then this would happen a: %00111010 (hl): %10010111 XOR ----------------------- new a: %10101101 > > i suppose it xor's the byte at adress hl... > > > > > I'm a bit confused, xor uses the a register, right? > > Then if you do xor (hl), does it then xor h with a, and l with a??? > > > > >