bnsokol@watrose.UUCP (04/06/87)
The recent anouncements by IBM included several new displays which are
driven by analog signals rather than digital signals like the old displays.
The way I understand it, digital signals on PCs are made up of four signals,
red, green, blue, and an intensity signal giving 16 colours. How does analog
work? What are the advantages of analog over digital? Does it allow for higher
frequency of scan rate and thus more colours and higher resolution?
Thanks in advance for the answers!
--
Brad Sokol, University of Waterloo, Waterloo, Ontario, Canada
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bnsokol@watrose NETNORTHsmvorkoetter@watmum.UUCP (04/06/87)
Analog also uses red, green, and blue, but no intensity signal. However unlike digital where each colour is present or not present, analog allows various amounts of each colour. If you have say 8 bits per colour, then these are converted to a proportional voltage for each colour (say 0 .. 5V).
dillon@CORY.BERKELEY.EDU (Matt Dillon) (04/13/87)
>The way I understand it, digital signals on PCs are made up of four signals, >red, green, blue, and an intensity signal giving 16 colours. How does analog >work? What are the advantages of analog over digital? Does it allow for higher >frequency of scan rate and thus more colours and higher resolution? With Analog, you usually have R,G, and B but no intensity signal. Each R, G, B is an analog voltage rather than a digital voltage. So, to get a pallette of 256K, each R, G, and B would have 64 levels. The advantages over digital are simply that you get a much broader color range (assumming your monitor has analog inputs). Analog does not mean higher frequency as far as the monitor is concerned. However, you would need a larger memory bandwidth on the processor bus assumming, say, 8 bit planes generating 256 colors out of a pallette of 256K. Analog looks *much* better than digital. Remember, before analog came along people were trying to get around the 'digital' monitors by modulating the digital outputs. -Matt