inloop: in a,(stdin) ; Grab a character from the keyboard ld (hl),a ; stick it in main memory inc hl nine: cp #00111000 ; ASCII 9 jp z inloop ; If we got a 9, then read the next character. eight: cp #00111001 ; 8 jp z inloop ; ditto rest: and #00110000 ; 0-7 have this bit pattern but we don't care about the lower nybble. cp #00110000 jp z inloop