x=320 : y=240 : r=200 : sq=45
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sync on : sync rate 0
 
DO
   r=rightkey() : l=leftkey()
   sq=sq+r-l
 
   For a = 0 to 359
      line x+sin(a)*(r+sq-360),y+cos(a)*(r+sq), x+sin(a+1)*(r+sq-360), y+cos(a+1)*(r+sq)
   Next a
 
   sync : cls
LOOP