IX and IY registers

Undocumented instructions for IX and IY registers

If an opcode works with the Registers HL, H or L then if that opcode is prefixed by 0xDD then it will also work on the appropriate IX, IXh or IXl registers, with some exceptions.

The 0xFD prefix would also work but for the IY, IYh or IYl registers

The exceptions are instructions like LD H,IXh or LD L,IYh where it isn't clear from the opcode which register the 0xFD or 0xDD prefix should operate against.


LD IX undocumented instructions

Undocumented instructions for LD IX

LD IY undocumented instructions

Undocumented instructions for LD IY

Undocumented Math instructions with the IX register

Undocumented math instructions for IX register

Undocumented Math instructions with the IY register

Undocumented math instructions for IY register

Last modified November 9, 2021: Add undocumented IX instructions (d92b620)