10REM (C) J.ILSLEY 1992.  
   20*TV255,1
   30MODE1
   40VDU5
   50VDU29,640;512;
   60FOR S=20 TO 500 STEP 40
   70GCOL3,RND(3)
   80VDU19,RND(3),RND(8)-1;0;
   90FOR X=-S TO S STEP 8 
  100MOVE-S,X:DRAW S,-X
  110MOVE X,-S:DRAW-X,S
  120NEXT X,S
  130GOTO 70