Configuring X

Q: Changing Screen Resolution

Everything on my desktop looks tiny. How do I change my screen resolution?

A. Use Xconfigurator

After you have installed Red Hat Linux, you may want to change your screen resolution, so that objects will fit better on your desktop. You can adjust the resolution with Xconfigurator, a tool which allows you to modify your X Window System settings.

To use Xconfigurator, you must log in as root and at a shell prompt, type Xconfigurator to start the application. The opening screen will look like Figure 13-3.

TipOther Ways To Start the Xconfigurator

You can start Xconfigurator in two other ways, both of which give you access to additional configuration tools.

From the menu in GNOME or KDE, go to System => Text mode tool menu; or, from a shell prompt, type setup. Both methods will produce a menu of items which you can configure, such as X, your sound card, mouse, and other features.

Figure 13-3. The Opening Dialog of XConfigurator

To navigate and make selections, use the [Tab] key. When your selection is highlighted, press the [Enter] key.

NoteIs Your Hardware Supported?

Make certain that your monitor and graphics card are supported for Red Hat Linux. To check, visit the Hardware Compatibility List at

To continue, [Tab] until the Ok button is highlighted and press [Enter]. Xconfigurator will then probe your system for your video card, and suggest the correct X server to match your system, as in Figure 13-4. Click the Ok button to proceed.

Figure 13-4. Results of Video Card Probe

Next, pick your exact monitor make and model number, as in Figure 13-5. You can often find the make and model number on the front or back of your monitor.

Figure 13-5. The Monitor Setup Dialog

You'll have quite a few monitor choices — the hash mark (#) indicates your position in the list. Use your [up arrow] and[ down arrow] keys to move through the list, or use the [Home], [End], [Page Up] and [Page Down] keys. You can also jump to the manufacturer's place on the list by typing in the first letters of the name (such as ViewSonic) on your keyboard.

TipMonitor Not On the List?

If you don't find your monitor among the listed makes and models, you can specify your monitor's horizontal and vertical sync frequencies by choosing Custom in the list. Refer to your monitor's documentation for information about its correct frequency rates. Be careful! Don't select a frequency range which exceeds your monitor's capacity, because you could damage or destroy it.

Once you have selected your monitor's make and model, a dialog will inform you that your card will be probed for its correct display settings. Don't worry if your monitor blinks during the process; that's normal.

TipIf You Don't Want Linux to Probe

You don't have to probe your video card. If you choose No when asked if you want to accept the settings on the Monitor Probe screen, the next dialog will ask you how much memory is on your video card, then you will be able to select your chosen resolution (see Figure 13-6).

Figure 13-6. Select Video Modes

You can choose modes ranging from 8-bit to 24-bit, depending on the power of your computer and how many colors you want displayed. In each of the mode columns, you'll find resolution choices listed; using your [Tab] key, position the cursor in the boxes next to your chosen resolution. Select one by pressing [Space].

TipChoosing More Than One Resolution?

You can select more than one screen resolution — for example, if you prefer 800x600 and 1024x768, you can adjust your resolution at any time without opening Xconfigurator. To do this, use the [Ctrl]-[Alt]-[+ (plus)] or [Ctrl]-[Alt]-[- (minus)] keys to switch between resolutions.

When you're finished making your selections, press Ok.

Next, your video settings will be tested. You will see a graphical screen, with a dialog asking whether your settings appear correct. Following this dialog, another will ask whether you want a graphical login screen; if you answer Yes, you will have a graphical screen when you log in to your system. A final dialog will inform you of the location of your video configuration file (/etc/X11).

Now, log out, then log in again to your new screen resolution.