> When I switched to a flat screen (after the CRT monitor died), the > adjustment time was also the biggest disappointment. As you mention, > it usually takes 1, often even 2, seconds to recover after the > blanking interval.
(Cognitive dissonance - "blanking interval" is a technical term in video, meaning something inconsistent with your usage here.) > What I can't understand is what causes the blanking interval. Based on your description, I think this is happening whenever the display is resyncing to the signal. Unlike analog monitors, flatscreens seem to do this largely in software (many of them even put up some kind of user notification while doing it). I think it happens whenever the sync signal does something unexpected for the current mode. This can be a resolution change (since that entails a change of at least one sync frequency[%]) or it can be a too-large phase glitch. I suspect your 10% of the time when it doesn't resync corresponds to switchings that don't change sync frequencies and happen to occur such that the sync phase glitch is small enough to not trigger the auto-readjustment. My guess is that the host is re-initting the display hardware, probably resetting sync to a top-of-screen. If this happens to occur close enough to the former top-of-screen, the sync signal may appear close enough to uninterrupted for the monitor to continue running without readjustment. I may not be describing it well - but I don't see anything in your description which is inconsistent with the theory in my head. [%] In theory, a resolution change may not entail a sync glitch if you are changing just the horizontal resolution, and you're changing the pixel clock as well such that the horizontal scan frequency is unchanged. I suspect such changes are rare enough to "never" happen. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
