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Maths (Arithmetic): MULTU

[BBC Micro disc version, Docked]

Name: MULTU [Show more] Type: Subroutine Category: Maths (Arithmetic) Summary: Calculate (A P) = P * Q
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * GCASH calls MULTU * TT24 calls MULTU

Do the following multiplication of unsigned 8-bit numbers: (A P) = P * Q
.MULTU LDX Q \ Set X = Q BEQ MU1 \ If X = Q = 0, jump to MU1 to copy X into P and A, \ clear the C flag and return from the subroutine using \ a tail call \ Otherwise fall through into MU11 to set (A P) = P * X