> The older style monitors which had a nine pin connector
> were analog devices.  With the advent of the VGA monitor
> (or maybe it was the short-lived EGA), the wiring was boosted to
> a 15 pin connector and became a digital signal.
>
> In the pre-VGA/EGA world, the video card had to convert
> the digintal data into the three primary colors and output
> analog signals to the monitor.  Now that conversion
> circuitry is built inside the monitor.

        Actually amazingly it is the other way around. Pre VGA technologies were
predominantly digital technologies, this resulted in cheaper video adapters
(since no high speed DAC was needed, although onboard memory was the most
expensive part, and still often is). VGA is a completely analog technology,
the video card, aside from creating the sync signals, has a DAC that
converts the colour for every pixel into a specific amount of red, green and
blue signal. This is why the amount of colours you can display is limited by
the video adapter, not the monitor. So far this has been great because
analog technologies, being continuous, allow an almost unlimited of screen
resolutions and colour depths. However there have been problems. Being an
analog signal, signal strength is very important, that is why monitor
extension cables make the video fuzzier with faded colours. Give it a few
decades and monitors will most likely all be digital again. TTYL

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