   10SYS "Brandy_TekEnabled",1,115200
   20MODE 74
   30VDU5:CLG
   40S%=8
   50ORIGIN 1024,780
   60FOR X%=-1024 TO 0 STEP 2
   70M%=-780
   80FOR Y%=-1212 TO 1400 STEP S%
   90V%=(Y%+FNA(X%,Y%))/2
  100IF M%<V% THEN M%=V%: PLOT 69,X%, V%: PLOT 69,-X%,V%
  110NEXT Y%
  120NEXT X%
  130VDU4:END
  140DEF FNA(X%,Y%)
  150LOCAL A%
  160A%=SQR(X%*X% + Y%*Y%)
  170=SIN(RAD(A%)*2)*200-A% DIV 5
