DAS - 8086

Decimal adjust After Subtraction. Corrects the result of subtraction of two packed BCD values. 
Algorithm: 
If low nibble of AL > 9 or AF = 1 then: AL = AL - 6 & AF = 1
Else If AL > 9Fh or CF = 1 then:  AL = AL - 60h & CF = 1

Syntax

DAS

Example

MOV AL, 0FFh  ; AL = 0FFh (-1)
DAS           ; AL = 99h, CF = 1
RET

Output / Return Value

Limitations

Alternatives / See Also

Reference