SCREEN 12 prt2 = &H379 1 FOR x = 0 TO 630 c = INP(prt2) IF c <> 127 THEN y = y + 1 ELSE IF y > 0 THEN y = y - 1 END IF LINE (x + 6, 0)-(x + 6, 479), 12 LINE (x, 0)-(x, 479), 0 LINE (x, 0)-(x, y), 15 'FOR a = 1 TO 1000 'NEXT a NEXT x GOTO 1