8XXJ ...[??? UNSETBIT SECT CENT FGN 9 DOC   
 8Y7B    #   
 8YM2    #     THIS MACRO UNSETS BIT %A OF WORD %B   
 8^6L    #   
 8^L=    #MAC  UNSETBIT  
 925W          FLIPS    %B,%A
 92KG    #NOR