[Original] ATI Video Card set dual-Display

After adding a monitor to the Ubuntu 12.04 system, the system can only display images, or only display on the screen of the notebook. The other screen cannot be used. I searched the internet for a solution, the following method can be used to solve the problem:

Edit the/etc/X11/xorg. conf file and add the following content to Section "Screen:

Virtual 4000 3000

Restart xwindow

The shortcut key for restarting xwindow is Ctrl + Alt + Backspace. This shortcut key is disabled by default and can be changed in the shortcut key settings.

Or use sudo init 6 to restart.