==== Registers ====
* r or ,r̃: 000=B, 001=C, 010=D, 011=E, 100=H, 101=L, 111=A (110 is treated separately)* s or ,s̃: 000=B, 001=C, 010=D, 011=E, 100=IXH/IYH, 101=IXL/IYL, 111=A (110 is treated separately)
* pp: 00=BC, 01=DE, 10=HL, 11=SP
* p̃p̃: 00=BC, 01=DE, 10=HL, 11=AF