AAS              ASCII Adjust after Subtraction      Flags: O D I T S Z A P C
                                                            ?       ? ? * ? *
AAS
 
          Logic:    If (AL & 0Fh) > 9 or AF = 1 then
                        AL  AL - 6
                        AH  AH - 1
                        AF  1;  CF  1
                    else
                        AF  0;  CF  0
                    AL  AL & 0Fh
 
    AAS corrects the result of a previous subtraction of two valid
    unpacked BCD operands, changing the content of AL to a valid BCD
    number. The destination operand of the subtraction must have been
    specified as AL. The high-order nibble of AL is always set to 0.
 
  --------------------------------------------------------------------------
   Operands                  Clocks   Transfers  Bytes   Example
   no operands                 4          -        1     AAS
  --------------------------------------------------------------------------
 
       Note:          Unpacked BCD stores one digit per byte; AH contains
                      the most-significant digit and AL the least-
                      significant digit.

Seealso:


 AAA 
 AAD 
 AAS 
 SUB 
 SBB 
 DAS 
 Flags