MUL - Unsigned Multiply

        Usage:  MUL     src
        Modifies flags: CF OF (AF,PF,SF,ZF undefined)

        Unsigned multiply of the accumulator by the source.  If src is
        a byte value, then AL is used as the other multiplicand and the
        result is placed in AX.  If src is a word value, then AX is
        multiplied by src and DX:AX receives the result.  If src is
        a double word value, then EAX is multiplied by src and EDX:EAX
        receives the result.  The 386+ uses an early out algorithm which
        makes multiplying any size value in EAX as fast as in the 8 or 16
        bit registers.

                                 Clocks                 Size
        Operands         808x  286   386   486          Bytes

        reg8            70-77   13   9-14  13-18          2
        reg16          118-113  21   9-22  13-26          2
        reg32             -     -    9-38  13-42         2-4
        mem8        (76-83)+EA  16  12-17  13-18         2-4
        mem16     (124-139)+EA  24  12-25  13-26         2-4
        mem32             -     -   12-21  13-42         2-4


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