Dual Shift Operations

Undocumented instructions that perform two actions at the same time

There are a few undocumented instructions that performs an action and then copies the result into a register.

For example the official RLC (IX+nn)0xDDCBnn06 instruction operates on a specific memory address, however the undocumented RLC B,(IX+nn)0xDDCBnn00 instruction does the same thing but then copies the result into the B register.


RL Rotate bits left with Carry and store in register

Undocumented Rotate bits left with carry and store in register

RLC Rotate bits left with Carry and store in register

Undocumented Rotate bits left with carry and store in register

RR Rotate bits right with Carry and store in register

Undocumented Rotate bits right with carry and store in register

RRC Rotate bits right with Carry and store in register

Undocumented Rotate bits right with carry and store in register

SLA Shift bits left with Carry and store in register

Undocumented Shift bits left with carry and store in register

SLL Shift left Logical and store in register

Undocumented Shift left logical and store in register

SRA Rotate bits right with Carry and store in register

Undocumented Rotate bits right with carry and store in register

SRL Rotate bits right with Carry and store in register

Undocumented Rotate bits right with carry and store in register

Last modified November 9, 2021: Add undocumented RES r,n,(IX+d) (bd7d415)