20 D1 = 60:D2 = 73:D3 = 77
30  DEF  FN FX(A) =  COS(D) *Z
40  DEF  FN FY(A) =  SIN(D) *Z
50  FOR D = 0 TO 6.28  STEP 0.01
55  HCOLOR= 3
60 Z = 55: GOSUB 100
65  HCOLOR= 1
70 Z = 53: GOSUB 100
80  NEXT D
82  HCOLOR= 7:Z = D3:: FOR D = 0 TO 6.28  STEP 0.1
83 X =  FN FX(1):Y =  FN FY(1): HPLOT 140 -D1 * COS(D),96 -D1 * SIN(D) TO 140 -X,96 -Y: NEXT D
90  END 
100 X =  FN FX(1):Y =  FN FY(1)
110  HPLOT 140,96 TO 140 -X,96 -Y
120  RETURN