;; A useful procedure to display a 8-bit number in binary ;; .txt_output equ &bb5a ;;------------------------------ ;; DISPLAY A BYTE IN BINARY FORM ;; ;; Enter: ;; A = 8-bit value ;; ;; Exit: ;; AF corrupt. ;; B corrupt. ;; All other registers preserved .display_binary ld b,8 ;number of bits to display .get_bit rlca ;rotate current top bit into carry ;if the bit was 1, the carry is set. (i.e. carry=1) ;if the bit was 0, the carry is reset. (i.e carry=0) push af ld a,"0" ;ASCII character for bit value adc a,0 ;add carry, if carry is set A="1", otherwise A="0" call txt_output ;display character onscreen pop af djnz get_bit ;loop, until all bits have been displayed ret