Extract Monitor Modeline

Xerop · 06-07-2006, 10:30 AM

Hi I have a geforce 6600gt. I had connected a vga cable to the B output. With this configuration fedora could not detect my monitor properly and gave me refresh rates of 79hz which my 20.1 lcd monitor doesn't support (monitor said that that was the refresh rate) I have now connected a DVI cable (A output) to the monitor and it was properly detected. How do I extract the current modeline to use with the vga cable?

This all should work fine it does in other distributions like gentoo. I just got sick of compiling everything...

(I need the VGA cable for a kvm switch) The DVI cable makes this hard to use even though gives better quality. (A dvi kvm switch costs $250, so no I wont buy one. )

Thanks in advance.

jschiwal · 06-07-2006, 11:55 AM

You could use the "gtf" program to generate a modeline at the refresh rate you want.
gtf <horizontal> <vertical> <refresh> -x

Then add the modeline to the Monitor section.

It will generate a modeline like this:

Code:

  # 1024x786 @ 60.00 Hz (GTF) hsync: 48.84 kHz; pclk: 65.64 MHz
  Modeline &quot;1024x786_60.00&quot;  65.64  1024 1080 1184 1344  786 787 790 814  -HSync +Vsync

You may need to lop off the ".00" from the title, I'm not sure whether X will parse the .00 part properly. In the "Screen" section of your xorg.conf file,
make sure to add the "_60" part to the "Modes" entries:

Code:

Section &quot;Screen&quot;
  DefaultDepth 24
  SubSection &quot;Display&quot;
    Depth      15
    Modes      &quot;1280x800&quot; &quot;1280x768_60&quot; &quot;1024x768&quot; &quot;1280x600&quot; &quot;1024x600&quot; &quot;800x600&quot; &quot;768x576&quot; &quot;640x480&quot;
  EndSubSection

Do this with the monitor you will use, when using the KVM switch. I'm not certain is vga vs dvi cable will effect the -HSync +HSync part.
These modeline values are just an example for illustration. Please use your own of course. ---- As a shortcut, since you are using SuSE, you could try hooking up the same monitor you will use in the end and try running "sax2". If the initial sax display shows up, click on save and use that. ---- PS. When I edited this post, the quotes got converted to html markup. Sorry about that.