Well, other question, how can i add 8 to a? ld a,(left_y) ; left_y contains the vertical position of the top of my sprite ld e,a ld a,5 ; the horizontal position is always 5 ld bc,SpritePaddleTop ; the top of my sprite call SPRXOR ; call movax' sprite routine ;call _grbufcpy_v (must I include this line here?) ld d,8 ; } Why doesn't this work??? add a,d ; } call SPRXOR call _grbufcpy_v