"Mode not supported"

cckuo chechun_kuo at sis.com
Tue Aug 1 05:48:13 PDT 2006

If you use the XFree86, you can get a new config file by typing "XFree86
-configure" under your user's home directory. 
If you use the Xorg, you can get a new config file by typing "Xorg
-configure" under your user's home directory.

If the EDID, a VESA standard used to describe your monitor's resolution,
works normally, you will see a brand new Monitor section in the new config
file, which may contain your monitor's manufacture's name and the proper
Hsync and Vsync value. Then copy that part to the config file you take to
activate your Xserver.
Sincerely Yours,
-----Original Message-----
From: xorg-bounces at lists.freedesktop.org
[mailto:xorg-bounces at lists.freedesktop.org] On Behalf Of Timothy Murphy
Sent: Tuesday, August 01, 2006 6:56 PM
To: xorg at lists.freedesktop.org
Subject: "Mode not supported"

When I boot my AMD Athlon64 (Targa) machine
with a Gericom LCD monitor,
I get the message on the monitor
"Mode not supported
H = 36.8  V = 82.2"

It is true that this is out of the range
specified for the monitor: H = 31-80, V=60-75.

However, in xorg.conf I have
ModelName "LCD Panel 1024x768"
HorizSync 31.5-67.0
VertRefresh 60.0-75.0

So it seems that either the setting in xorg.conf is ignored,
or else the monitor misunderstands the message it gets.

Commenting out the HorizSync and VertRefresh lines in xorg.conf
does not remove the message, but does reduce the resolution,
I think to 640x480.

Kernel 2.6.16* works despite the message,
but 2.6.17* hangs (possibly for some other reason).

I've tried running System=>Display (under KDE),
but this does not alter the settings.

Does anyone understand this?
How can I correct the HSync and VRefresh limits?

Incidentally, there is no such problem with Windows;
the monitor works fine at 1240x1024 with 32 bits.

Timothy Murphy  
e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland
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