1 SCREEN 2:COLOR 5,0,2 :CLS: px = 50: py = 50: tr = 3 
2 cx=INT(RND(1)*192):cy=INT(RND(1)*256):FOR t=1 TO 20:CIRCLE(cy,cx),t:a$=INKEY$
3 CIRCLE(py,px),3,0:CIRCLE(cy,cx),t,0:py=py+(tr-2*(tr/(ABS(tr))))*2
4 px=px+(tr /(ABS(tr)))*(2):CIRCLE(py,px),3,1:IF a$<>"" THEN tr=tr-2:a$=""
5 IF py > 256 OR px > 192 OR py < 0 OR px < 40 THEN tr = tr - 2
6 IF py < cy + 20 AND py > cy - 20 AND px<cx+20 AND px>cx-20 THEN cls:GOTO 9
7 IF tr < -3 THEN tr = 3
8  NEXT: GOTO 2
9 x = cy: y = cx:PSET (x, y):FOR c=0 TO 360 STEP 30: FOR I=1 TO 8:z=3.141/180
10 z=z*(45*(I-1)+c):x=x+20*COS(z):y=y-20*SIN(z):LINE -(x, y):NEXT:NEXT:GOTO 1

