open window 640, 320
wid = 4
xcenter = -1: ycenter = 0
ms = 0
for xcoord = 0 to 639
   for ycoord = 0 to 160
       ms = 0
       ca =(xcoord-320)/640*wid+xcenter
       cb =(ycoord-160)/640*wid+ycenter
       x = 0: y=0

       for t = 1 to 20
           xnew = x*x-y*y+ca
           ynew = 2*x*y+cb
           x=xnew:y=ynew
           magnitudesquared=x*x+y*y
           ms = magnitudesquared
           if (magnitudesquared > 100) break
           //if(magnitudesquared < 100) then : color 0,0,0 : dot xcoord, ycoord : end if
       next t
       ms = ms+1
       if(ms > 250) then
       	    color 32,64,mod(ms,255)
            dot xcoord, ycoord
            dot xcoord, 320- ycoord
        elseif (ms > 150) then
            color mod(ms,255),64,32
            dot xcoord, ycoord
            dot xcoord, 320-ycoord
        else
            color 0,0,0
            dot xcoord, ycoord
            dot xcoord, 320-ycoord
        end if
    next ycoord
next xcoord