TILE HEIGHT 16
CLS
For Y=0 To 29:For X=0 To 79
If X+(Y<<1) And 2 Then BC=RGB(Myrtle) Else BC=0
TILE X,Y,RGB(CYAN),BC,1,1
Next :Next
For X=-25 To 24
For Y=-25 To 24
For U=0 To 1
For V=0 To 1
Q=PLOT(4+83*U,X+U,Y+V)
Next :Next
For U=0 To 2 Step .5
Q=PLOT(4+Sgn(U),X+(1 And U+.5),Y+(1 And U))
Next :Next :Next

Function PLOT(P,X,Y)
X0=320+7.5*X-6.5*Y
Y0=240+2*X+2.5*Y+29*Sin(A2(X,Y)*4+Sqr(X*X+Y*Y)/2)
If P=4 Then X1=X0:Y1=Y0
If P=5 Then Line X1,Y1,X0,Y0:X1=X0:Y1=Y0
X2=X0:Y2=Y0
PLOT=0
End Function

Function A2(X,Y)
If X=0 Then A2=1.57 Else A2=Atn(Y/X)
End Function