COM - One's Complement ;flags(N,Z,C)
COM opr ;(opr) < $FF - (opr) ;(DIR) 8 bit direct
COM ,X ;(X) < $FF - (X) ;(IX) indexed no offset
COM opr,X ;(opr+X) < $FF - (opr+X) ;(IX1) indexed/8 bit offset
Replaces the contents of M(opr) with its one's complement.