Regulus Berdin wrote: > Dmitry Kiryashov wrote: > > I see no problem there. jUST write xorwf K,w instead of xorlw K :) > I guess you're right. I goofed. Sorry! > regards, Hello Reggie. No sorry required. Just try apply efforts in reducing this 6 words code. This is very interesting idea and maybe often practically used. I have an idea to look through all possible combinations of W,R,K ie. every input and output value can be applied in normal or complement format. I think in some combinations within of 8 possible exist a smaller version of vertical adder/substractor. WBR Dmitry.