KVM switch - display resolution.

Matthew Kuiken matt.kuiken at verizon.net
Sat Nov 25 16:43:21 UTC 2006

Wow, this is really hard to follow with all the top posting...

My comment is in the middle:

Dave M wrote:
> It is a "Slim KVM Switch - 4 port". I cant find a model number on it. I 
> didn't think about restarting Gnome. Maybe that will work.
> Dave
> At 09:25 PM 11/24/2006 , Gary wrote:
>> For me if I don't plug the second monitor in when the system boots
>> then I don't get the display on it until I restart Gnome.
>> However a good quality KVM switch would tell the machine that the
>> monitor is plugged in even when you are switched over to another
>> monitor, hence the system should boot up in the right resolution. What
>> is the brand and model of KVM switch that you use, if I have stock, I
>> might be able to check it out!
>> Gary
>> On 11/25/06, Dave M <DaveM at mich.com> wrote:
>>> Here is my edited xorg.conf
>>> But this does not solve the problem.
>>> Still boots to 640x480 when the monitor is switched out.
>>> Section "Device"
>>>          Identifier      "Trident Microsystems CyberBlade/i1"
>>>          Driver          "trident"
>>>          BusID           "PCI:1:0:0"
>>> EndSection
>>> Section "Monitor"
>>>          Identifier      "VL1918"
>>> #       Option          "DPMS"
>>> EndSection

You need to add a couple of lines here.  Since the monitor is not hooked 
up, xorg will not be able to find its horizontal and vertical ranges, 
and so it is probably defaulting to the ranges supported by VGA.

Add the lines:
	HorizSync	31-80
	VertRefresh	56-75

to the monitor section.  If you boot with your monitor plugged in, you 
should be able to find the correct ranges for these settings in 

If you can't find it there, search for a modeline generator on google, 
enter the video resolution you want, and just make sure that the range 
you put in xorg.conf includes the horizontal and vertical frequencies 
for that mode.

There is one warning that I must add here.  It is possible to damage 
some monitors by inputting a signal that is outside of their spec range. 
  It would be safer to find the ranges above by looking at the specs for 
your particular monitor.


<snip rest>

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