Command: DAS - Decimal Adjustments
Arguments: none
Usage: DAS
Effects: DAS should be used after a one-byte SUB instruction whose destination was the AL register: by means of examining the value in the AL and also the auxiliary carry flag AF, it determines whether either digit of the addition has overflowed, and adjusts it (and sets the carry and auxiliary-carry flags) if so.
Flags to be set: CF=1 and AF=1 if subtraction has overflowed