Command: MOVSB - Move Byte from String to String
Arguments: none
Usage: MOVSB
Effects: Copies the byte at [DS:SI] or [DS:ESI] to [ES:DI] or [ES:EDI]. It then increments or decrements (depending on the direction flag: increments if the flag is clear, decrements if it is set) SI and DI (or ESI and EDI).
Flags to be set: none