aad
AL + (AH x 10) -> AL 0 -> AH
aad prepares two unpacked BCD digits for a division operation that yields an unpacked result. The least-significant digit is in AL; the most-significant in AH.
aad prepares the AL and AH registers:
AL + (AH x 10) -> AL 0 -> AH
AX is then equal to the binary equivalent of the original unpacked two-digit BCD number.
Adjust the AL and AH registers for a division operation by setting the AX register equal to the original unpacked two-digit number:
aad