[H-GEN] onefang's theory of monitor speed. Was: flat panel monitors with Linux?

[Christopher Biggs]

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David Seikel <won_fang at yahoo.com.au> moved upon the face of the 'Net and spake thusly:

>
> I'll be willing to admit that newer monitors are doing more safety checking
> to avoid damage, but that doesn't explain the long delays, or the fact that
> the delays are getting longer.  How long does it take to check a dozen
> modeline parameters?

You misunderstand what is happening.     The monitor knows nothing
about these "modelines" of which you speak.    

The video card is generating an analog signal on a bunch of colour
pins, and sync pulse waveforms on two pins, one for horizontal sync
and one for vertical sync.  The monitor has to figure out the
frequency of all these pulses by fourier analysis, using 
phase-locked-loop trickery, or simply by scanning across all values
until it detects something that makes sense.

One upon a time hsync ranges were maybe 25-35khz and vsync were
25-50Hz, nowadays the possible ranges are more like 25-200khz and
25-160Hz, so the scope of analysis that the monitor has to do to "lock
on" to the video signal is VASTLY expanded.

--cjb



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