I know XOR A modifies the flags, but I don't need them for this purpouse so they can be discarded. Now I have clear XOR usage.
I misunderstood its usage. I was sure the Xor was between a reg and itself. Now I see it's between reg and A. Thx
"XOR r" instructions are just shortcuts for "XOR A,r", that meaning "A = A XOR r". The same goes for AND, OR and other instructions that take only one parameter, like CP.