RANDOMIZE TIMER
SCREEN 12
a = 2                                      'a=1
b = a / 2                                  'b=.5
WINDOW (0, 0)-(a, a)
x = RND * a
y = RND * a
DO
  n = INT(RND * 3) + 1
  IF n = 1 THEN x = .5 * x: y = .5 * y
  IF n = 2 THEN x = .5 * (b + x): y = .5 * (a + y)
  IF n = 3 THEN x = .5 * (a + x): y = .5 * (b * y)
  PSET (x, y)', INT(RND * 15) + 1
LOOP UNTIL INKEY$ = CHR$(27)


'    SYNTAX FOR DS>( AND IS<(
'ds<(var,val)     'var=var-1
'if var<val then skip next command
'else go on normally