The following is the fastest possible '''multiplication routine''' (in a little specialised way) for the CPC, coded by [[Prodatron]] for the [[Voyage 1993 Megademo]] and the [[Digital Orgasm]] demo. It works with signed values and is mainly used for 3D graphic calculations. You can change it to HL=HL*A by removing LD A,H in front of every RET command inside the MULxxx sub-routines, but than in this case A has to be positive.
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