Quick how-to to make dual screens work on a Radeon dual-head video card on PCLinuxOS. In my case, that's a Radeon 5850.
1. Connect both monitors
2. Your ATI drivers (flgrx) should be installed by default, but you can first upgrade them. Open Synaptic, search for flgrx and upgrade, if any.
3. Install the Catalyst Control Center, search for that or fglrx-control-center at Synaptic. It may not install an entry in any of the menus.
4. At PCC, choose the flgrx driver (enable transparency for visual effects to work), choose your monitors (if in doubt choose "plug-and-play"), and resolutions (if in doubt choose "auto"). Reboot.
If you get sent to the command line upon boot, type XFdrake as root, choose the same driver, then DONT REBOOT, just type startx immediately.
5. Run the Catalyst Control Center
Contrary to common sense, it's installed under the name of amdccclesu. Yes, I know. Be happy.
So type amdccclesu in a console as root.
6. Once on Catalyst Control Center:
6a. Check your monitors' resolutions, to make sure they are set up the way you want.
6b. Rearrange the order of monitors. Just drag them around inside that little window until you have the set up you want.
6c. On the Multi-Display tab, choose Multi-Display desktop with display (x). Apply changes. Reboot.
Here's my monitor 1 configuration:
Here's my monitor 2 configuration:
7. The dual monitor setup should be in place by the time you get back to your desktop.
Say, for instance, that you want a monitor 1 as main monitor, and monitor 2 as an extension of the desktop on the right of monitor 1. If the main panel, and other panes if your have them, are on the wrong monitor, it may not mean the Catalyst Control Center screwed up, just drag the panels to the location you want.
If, and when, you get your dual-screen setup working the way you want, for Christ sake, please make a backup of your /etc/X11/xorg.conf file!!