Thursday, December 13, 2007

Ubuntu 7.10, the T61 and External Monitors

I had a spot of bother trying to use an external monitor with Ubuntu 7.10 Gutsy Gibbon on a Lenovo T61. My T61 has an Nvidia Quadro 140M card and I'm using the proprietary (restricted) drivers.

I got a Lenovo Mini-dock and a Lenovo D221 monitor with my T61. When I connected everything up and put my T61 on the mini-dock and started it, everything appeared on the external monitor up to the Ubuntu splash screen with the progress bar. Right after that, the external monitor went blank and the T61's screen took over. (I think that happened when the X server was started, but not sure.) The same thing happened when I connected the external monitor to the T61 directly (not through the mini-dock).

To resolve this:
  1. Connect the external monitor to the laptop directly
  2. Open up a terminal, get root access using "su", and type "nvidia-settings &" at the prompt. This is a configuration program from the package "nvidia-glx-new" (I think it gets installed when you install the restricted nvidia drivers, but not sure).
  3. Within nvidia-settings, select "X Server Display Information". It should show two monitors in a little box called "Layout". The external monitor may be disabled.
  4. Click on the external monitor's icon, then click "Configure", then select "Separate X Screen".
  5. Click on the laptop screen's icon (which is probably enabled), then click "Configure", then select "Disabled".
  6. Note: This step will overwrite the X Confuration File (usually /etc/X11/xorg.conf). You may first want to backup that file to something like xorg.conf.bak.01. When you've backed it up, click "Save to X Configuration File".
When I restarted my X Server (or restarted the computer) after this, all output came out only on the external monitor, which is what I wanted.

However, this didn't solve the problem when I put the T61 on the mini-dock. I also had to connect the T61 and the external monitor to the mini-dock, and then repeat steps 2-6 with the T61 on the mini-dock.

Finally, when the T61 is not connected to the external monitor in any way, it should continue to work as usual. The above configurations don't affect this.

Caveats:
  1. After doing this, there is an Nvidia splash screen every time the X Server is started up. This can be removed by editing /etc/X11/xorg.conf, but I don't detail that here.
  2. After this reconfiguration, I began noticing that my GL Desktop window manager crashes very frequently. When that happens, I can resolve it by running System > Preferences > GL Desktop. But it is a bother.

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