DECLARE SUB delay (tim!)
SCREEN 12
DIM h(3)
FOR i = 0 TO 3                       'h(0)=&h1111
num$ = RIGHT$(STR$(2 ^ i), 1)        'h(1)=&h2222
h(i) = VAL("&H" + STRING$(4, num$))  'h(2)=&h4444
NEXT i                               'h(3)=&h8888
DO
  FOR i = 0 TO 3
    LINE (100, 100)-(539, 379), 13, B, h(i)
    delay (.1)
    LINE (100, 100)-(539, 379), 0, B, h(i)
   key$ = INKEY$: IF key$ <> "" THEN EXIT DO
  NEXT i
LOOP

SUB delay (tim)
  tim = tim + TIMER
  WHILE TIMER < tim
  WEND
END SUB