The stock A1000 has a color composite output and requires bit 9 (COLOR_ON)
set in  bplcon0  to create a color composite display signal. without the
addition of specialized hardware, the A500, A2000 and A3000 cannot
generate color composite output.

   NOTE:
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   The color burst enable does not affect the RGB video signal. RGB
   video is correctly generated regardless of the output of the
   composite video signal.