Maths (Arithmetic): MLU2

       Name: MLU2                                                    [Show more]
       Type: Subroutine
   Category: Maths (Arithmetic)
    Summary: Calculate (A P) = |A| * Q
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * STARS1 calls MLU2
             * STARS6 calls MLU2


 Do the following multiplication of a sign-magnitude 8-bit number P with an
 unsigned number Q:

   (A P) = |A| * Q


.MLU2

 AND #%01111111         \ Clear the sign bit in P, so P = |A|
 STA P

 JMP MULTU              \ Call MULTU to calculate:
                        \
                        \   (A P) = P * Q
                        \         = |A| * Q
                        \
                        \ and return from the subroutine using a tail call