// Spiral

     Call graph on
     Set c = 0; Set d = 1; Set s = 2
one: Set r = 1.0; Set x = 0.0; Set y = 0.0
two: Call read quit key
     Call move to (x + 320, y + 240)
     Set x = r * cos(r)
     Set y = r * sin(r)
     Call line color (c)
     Call line to (x + 320, y + 240)
     Set r = r + (1 / r)
     Set n = (n + 1) % s
     If (n = 0) Set c = 10 - c
     If (r < 400) Goto two
     Set s = s + d
     If (s = 50) Set d = -1
     If (s = 2)  Set d = 1
     Goto one