It's probably a hardware hack for PAL or NTSC, allowing a pixel clock to be used that is an exact harmonic of the colour subcarrier. Without that, if the video DAC's reconstruction filter doesn't have a sharp enough slope, any remnants of the pixel clock would cause quite horrible vertical banding in hue/saturation. It's probably not an issue these days, but 10+ years ago video DACs were pretty crap.
(I worked on digital video hardware many moons ago, sorry for the bizarre braindump) :-)
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timeasmymeasure
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Date: 2004-06-28 06:52 pm (UTC)(I worked on digital video hardware many moons ago, sorry for the bizarre braindump) :-)