5 d1,0:d0,0:d7,10,9:XM=105:YM=105
6 XC=.77:YC=.6:T=22:S=40
7 XL=-1.4:XR=1.4:YO=-.9:YU=1.2
8 DX=(XR-XL)/XM:DY=(YU-YO)/YM
9 FORN=0TOYM:Y1=YO+N*DY:FORM=0TOXM:X=XL+M*DX:Y=Y1:K=0
10 X2=X*X:Y2=Y*Y:Y=2*X*Y-YC:X=X2-Y2-XC:K=K+1:IF(K<T)AND(X2+Y2<S)THEN10
11 U=M+53-N/2:U1=U+1:V=N+80:V1=V-3*(K-1)
12 d U,V,U,V1,3:d U1,V,U1,V1,2:d U,V1,U1,V1,1
13 NEXT:NEXT
14 WAIT198,255