rem VDU 23,22,width;height;charx,chary,ncols,charset
 vdu 23,22,1125;750;32,32,16,0:rem nikon d3300 size ratio (xy.5)
      origin 1125,750:rem center poiter moved to center of the screen
      :
      for z%=0 to 1125
        c%=255-255/1125*z%
        c1%=sin(rad(z%))*255 or 64
        x%=z%
        y1%=750/1125*z%
        y2%=-750/1125*z%
        y%=750/1125*z%
        :
        :rem setting colours
        colour 1,c1%,0,0:rem red
        colour 2,0,c1%,0:rem green
        colour 3,0,0,c1%:rem blue
        colour 4,c1%,c1%,c1%:rem white
        :
        :rem lines
        gcol 1
        line x%,y1%,x%,y2%
        gcol 2
        line -x%,y1%,-x%,y2%
        gcol 3
        line -x%,y%,x%,y%
        gcol 4
        line -x%,-y%,x%,-y%
      next