Stack I/O, and Machine Control Instructions:

The following instructions affect the Stack and/or Stack Pointer:

 

PUSH          Push Two bytes of Data onto the Stack

POP           Pop Two Bytes of Data off the Stack

XTHL          Exchange Top of Stack with H & L

SPHL          Move content of H & L to Stack Pointer

 

The I/0 instructions are as follows:

 

IN            Initiate Input Operation

OUT           Initiate Output Operation

 

The Machine Control instructions are as follows:

EI            Enable Interrupt System

DI            Disable Interrupt System

HLT           Halt

NOP           No Operation