custom resolution for LCD in xorg.conf

I have a Samsung LN-S2641D LCD TV 26". I'm trying to configure it with CentOS, but I'm having issues. First off the system-config-display application doesn't list this device, obviously because it's new, so I'm attempting to choose generic LCD, but it doesn't have one listed with the TVs native resolution: 1360x768.

So I decide to go into /etc/X11/xorg.conf directly. But I see there is one parameter called "DisplaySize", and I have determined it's calculated by using the dotpitch of the screen multiplied by the native resolution.

Well, I've checked the specs of this thing, and the web, but I am unable to determine the dotpitch (DPI?).

Are there any utilities that will probe the LCD to determine that stuff?

Linux CentOS 4.4
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justcureiousConnect With a Mentor Commented:
If I get it correctly, you want to add the resolution 1360x768 to your xorg.conf file right?

So I would suggest you do this from a console/terminal:
1. backup your original xorg.conf file before you tamper with it, by doing
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup
2. edit xorg.conf using nano editor (NOTE: use any editor you're more familiar with instead if you like)
sudo nano /etc/X11/xorg.conf
navigate to the section "Screen", and go to subsection "Display" with the depth you're going to be using (if you're not sure just do it for every subsection) and add "1360x768_refreshrate" (including quotes) where refreshrate is the refresh rate of your TV. That's all you need to find out, I don't think you'll be needing the DPI of it..
(NOTE 2: ctrl-O saves the file and ctrl-X exits nano editor)
3. restart the X-server by hitting Ctrl-Alt-Backspace if you're already operating in GUI mode
OR from the console/terminal type
sudo /etc/init.d/gdm restart (for GNOME desktop environment)
sudo /etc/init.d/kdm restart (for KDE desktop environment)
If all went well, you should now be able to select that resolution from the list of available ones
4. if something went wrong and the X-server crashes into a blue screen with an informational message, DON'T PANIC!!!
just log into a console (hit alt-F1) and do
sudo cp /etc/X11/xorg.conf.backup /etc/X11/xorg.conf
and everything will revert to the way it was before you made any changes!!

Let me know if it helped
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