On Sun, Jan 22, 2012 at 2:30 PM, Mark Knecht <markkne...@gmail.com> wrote: > On Sun, Jan 22, 2012 at 10:58 AM, Michael Mol <mike...@gmail.com> wrote: >> On Sun, Jan 22, 2012 at 1:07 PM, G.Wolfe Woodbury <redwo...@gmail.com> wrote: >>> On 01/22/2012 12:42 PM, Mark Knecht wrote: >>>> >>>> I played a bit with get-edid | parse-edid. Logically that stuff even >>>> working says the VGA monitor cable is bidirectional. I started wondering if >>>> the KVM messes up the data coming back, or what else might be going on. >>>> Thanks for the ideas, Mark >>> >>> Many of the cheap KVM models do, indeed, mess up the EDID data coming from >>> the monitor. I suspect that this is from old design specs that have too >>> much pull-up/pull-down on the EDID lead since the boxen haven been >>> re-engineered for newer, higher resolution and higher speed monitors. >>> >>> I have had problems specifically with the BELKIN KVMs. >>> >>> It may also be that the video drivers for Linux are just enough different >>> (necessarily) from the MSFT drivers to not reliably sense the EDID return >>> signals. >> >> Concur. It sounds like the EDID block isn't making it back or is >> somehow messed up. x11-misc/read-edid would help in investigating that >> kind of issue. >> > > Yeah, I did that sort of stuff already. It didn't tell me anything > specific as best I could tell. However I haven't done it with the KVM > out. Maybe comparing the two responses would give some clues. > > Also, thanks for the pointer to xvidtune. Interesting little app. > QUESTION: Do you know how to get the data for each monitor/video card > combo? So far I haven't figured out how to tell it Screen2. Seems to > only give me Screen0 as best I can tell. > > I'm a bit nervous to just start trying things.
If you're not using Xinerama, you can specify screens by changing $DISPLAY. e.g. :0.0 is screen 0, :0.1 is screen 1, :0.2 is screen 2... -- :wq
