A dysfunctional video card can stop new Linux users in their tracks. Getting video card, monitor, and desktop settings tuned just right can take some doing, even for an experienced system administrator. Without a working graphical user interface, a desktop system can end up stuck in command line mode.
This chapter will help you get your video card, monitor, display, mouse, and keyboard all working happily together. It also points you toward resources where you can get further help if you need it.
All graphical user interface (GUI) activity in Fedora is based on the X Window System (www.x.org/X11.html)-often simply referred to as X. Likewise, most other Linux and UNIX systems are based on X. The open-source version of X that is included with all versions of Red Hat Linux and Fedora Core 1 is XFree86 (www.xfree86.org). As of Fedora Core 2, the X Window system is being taken directly from the X.org source code.
An interesting aspect of X is that the programs you use (X clients) don't have to run on the same computer as the X display (X server). This presents some very powerful possibilities, such as using low-end computers as displays while actual applications may actually be launched from more powerful computers on the network. (Some people are confused about the fact that the X server runs on the local display and the clients can run from remote displays, and pop up on the local display.)
A casual user will not even deal with any of the X configuration files directly, since the setup of those files is typically done during installation (where the video card can be automatically probed and configured) or using tools such as the Display Settings window (redhat-config-xfree86 command). If all goes well with those tools, the user can simply:
Boot to the GUI-During Fedora Core installation, if you successfully configured X, the default run level will be set to 5. This causes the computer to boot to a graphical login screen, so that X is running for each login session.
Run startx-If X was not configured, the computer will probably boot to run level 3. Runlevel 3 is a text-only mode. You may have to run the redhat-config-xfree86 or XFree86 commands to configure your video card and monitor. To start the GUI after running those commands, you can run the startx command.
X by itself is not very usable. Run the X command from a text log in and you get a plain gray screen with an "X" as your mouse pointer. There are no menus, windows, colors, panels or anything else you need to use a desktop. There are not even any controls to exit from X (press Ctrl+Alt+Fl to switch back to a virtual terminal and kill the X process).
You need to add a desktop environment, or at least a window manager, to be able to work with an X desktop. After X starts, by default you will see the GNOME desktop in Fedora and Red Hat Linux. GNOME provides the desktop environment: menus, panels, window borders, icons, and definitions of things such as how your keyboard and mouse behave. There are many window managers available for X, but Fedora Core lets you choose among the following:
GNOME-The GNOME desktop environment (www.gnome.com) is installed by default with most installation types of Fedora Core. On the surface, GNOME includes components to manage windows, set preferences through a Control Center, launch applications and applets from panels, and manage sessions and files. Underneath, there are libraries for creating applications that can take advantage of GNOME desktop features.
KDE-The KDE desktop environment (www.kde.org) provides more applications than its GNOME counterpart. In general, the KDE environment requires more RAM and CPU power than GNOME does to run effectively. However, KDE is also richer in features.
TWM-If you want a very simple display manager, without the overhead of panels, menus and everything else that comes with a full-blown desktop environment, you can bypass a full-blown desktop environment and set the window manager to TWM. The TWM desktop manager will run when you start X, with only a simple left-click menu to start applications.
Run the switchdesk command from the desktop to pop up a window that lets you select a different desktop environment or window manager. Restart X (by exiting the desktop and restarting it with the startx command) to use the new desktop.
If Fedora Core was able to detect and configure your desktop environment in such a way that you are happy with your desktop (video, mouse, and keyboard) when it starts up, then you might well be done with this chapter. However, if your desktop, mouse, or keyboard does not start up correctly or require further tuning, read on.