MODE 3
Map Reset
For U=0 To 319
 x1=U/256-1.255
 For V=0 To 479
   y1=V/256-1
   X=0:Y=X:Z=-2.4
   Do
     k=Sqr(X*X+Z*Z)-2
     d=1-Sqr(k*k+Y*Y)
     X=X+x1*d:Y=Y+y1*d:Z=Z+d
   Loop Until d<.01
   v1=Atn(Z/X)
   u1=Atn(Y/k)
   sColor(): Pixel U,V
   v1=3.13-v1
   sColor(): Pixel 639-U,V
 Next
Next

'Dim integer cm(15)=(0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15)
'Dim integer cm(15)=(0,15,7,1,0,0,0,0,0,0,0,0,0,0,0,0)
Dim integer cm(15)=(0,15,14,6,4,2,0,0,0,0,0,0,0,0,0,0)
Colour Map cm(),cm()
Do
 T=cm(0)
 For i=0 To 14:cm(i)=cm(i+1):Next
 cm(15)=T
 For i=0 To 15:Map(i)=cm(i):Next
 Map Set
 Pause 50
Loop

Sub sColor()
 p=Sin(Int((u1+v1)*40)*99)*98
 c=15 And ((u1-v1+p)*24*Abs(Sin(p)))
 Color Map(c)
End Sub