"Mode not supported"

Timothy Murphy tim at birdsnest.maths.tcd.ie
Tue Aug 1 03:56:21 PDT 2006

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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