1 SPEICHER:POKE 53280,0:POKE53281,0:PRINT""
2 CLEAR:START
10 FOR N=200TO100 STEP -2:A=N/300
20 FOR M=NTO100+NSTEP20
28 GOSUB2000
40 NEXT:BILD:NEXT
50 FOR N=99TO-100 STEP -2:A=N/300
60 FOR M=NTO100+NSTEP10
65 GOSUB2000:NEXT:BILD:NEXT
1000 FILM 129
2000 IF M<=1THEN RETURN
2010 B=4000/M:X1=-B*2:X2=-X1
2020 Y1=-B/2:Y2=Y1
2030 Z1=COS(A)*X1+SIN(A)*Y1
2040 Z2=COS(A)*X2+SIN(A)*Y2
2050 Y1=+SIN(A)*X1+COS(A)*Y1
2060 Y2=+SIN(A)*X2+COS(A)*Y2
2070 LINE Z1,Y1,Z2,Y2:RETURN