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Figure 4-17: The Red Hat individual package selection screen
GUI installation
2.11 Install and configure Xfree86 server
2.12Select Video card support (e.g., chipset, memory, support resolution(s))
2.13Select appropriate monitor manufacturer and settings (e.g., custom, vertical, horizontal, refresh)
2.14Select the appropriate window managers or desktop environment (e.g., KDE, GNOME)
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The installation of the GUI, or graphical user interface, is the next part of the installation process. Often, you configure a GUI interface in Linux by using XFree86, which is a freely redistributable Open Source implementation of the X Window System that runs on UNIX, Linux, versions of BSD, Mac OS X (Darwin), Solaris for the x86 platform, and OS/2. XFree86 is the base software that provides the support between the hardware and graphical user interface. The KDE, GNOME, Enlightenment, Blackbox, AfterStep, twm and fvwm windows managers all run XFree86 as the interface to provide hardware support. The ability of Xfree86 to provide hardware support is constantly being updated by the XFree86 Project, Inc., located at www.xfree86.org, and currently provides support for not only the x86 platform, (hence the X in Xfree86), but also for Alpha, PowerPC, Sparc, and in-the- works MIPS CPUs. As Xfree86 has evolved, it has provided better and better support for more variations of hardware, and also provides high-end 3-D support. Although most windows managers, such as enlightenment, use the Xfree86 X- Windows System, it is KDE and GNOME that are the most used windows managers on today’s Linux systems.
Obtaining video card information
When configuring a system to use Xfree86, you are often required to have detailed information about the video card and monitor. Although Xfree86 does an excellent job of detecting video cards, sometimes it will identify the class of the video card — S3 968, for example — but not the exact chipset, such as S3 968 with TI3026 chipset. Therefore, when installing the Xfree86 system, you should know the manufacturer and the model of the video card, the video card chipset, and the amount of memory that the video card contains. As Xfree86 evolves, this is becoming less
of a requirement.
Monitors suffer many of the same detection errors, which is partly due to the fact that monitors are created by so many different manufacturers. Xfree86 allows you to manually input the information to get the best performance out of your monitor. You need the following information in order to correctly configure the monitor:
The horizontal and vertical refresh rate in Hz
The maximum color depth (only on old monitors)
The maximum screen resolution
With this information in hand, it is time to configure the system. Figure 4-18 shows the menu in the Red Hat setup, and Figure 4-19 shows the Xfree86 menu.
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Figure 4-18: The Red Hat X configuration screen
Configuring the X windows system
To configure the X Windows system, you need to use the Xfree86 configuration utility. The screens in Figures 4-18 and 4-19 demonstrate the ability of Xfree86 to interface with other programs in order to provide hardware support for any windowing program or windows manager. Red Hat has placed a single menu that accesses the Xfree86 submenu for the Video Card menu shown in Figure 4-20.
The next Red Hat installation screen, shown in Figure 4-21, shows the manufacturers of the monitor. This is an extensive list, as Red Hat contains support for virtually every monitor that may be on a system. This corresponds to the Xfree86 menu for monitor selection.
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Figure 4-19: The introduction to configuration with XFree86 screen
The screen in Figure 4-21 enables you to select the depth of color and screen resolution. Color depth allows the system to display images as close to the true colors that a video card can provide. Selections usually include 16-bit, 24-bit, and 32-bit color.
These are implementations of binary math that provide 4 bits for 16 colors, 8 bits for 256 colors, 16 bits for colors, 24 bits for 1,6777,216 colors, and 32 bits for 4,294,967,296 colors. By allowing the selection of color depth, the installation enables the user to select between color quality and screen resolution.
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Screen resolution is the number of pixels used to fill the screen. By setting the screen resolution to 640 × 480, for example, means that the video card will use 640 pixels wide by 480 pixels high to fill the monitor. Therefore, if you select the setting of 1024 × 768, then the screen can contain more data but will be smaller in size than the screen resolution setting of 640 × 480. This is because the video card is now using 1024 — almost twice the number 640 — pixels wide and 768 pixels high to fill the screen. Selecting a higher screen resolution usually results in reduced color depth capabilities because the amount of memory on the video card provides the ability to select different color depths and screen resolutions. On this system, the screen resolution is set to 1024 × 768 and the color depth is at 16 bits or High Color, as shown in Figure 4-22.
Figure 4-20: The Xfree86 video card selection screen
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Figure 4-21: The Red Hat monitor configuration screen
Because the video card has only 4MB of memory, the color is limited to 16 bits at 1024 × 768, but if you select 800 × 600, you can use 24-bit color, as shown in Figure 4-23.
The XFree86 menus are a little different because this task is broken down into two steps:
1.Select the resolution capabilities of the monitor. Notice in Figure 4-24 that the installer doesn’t choose by brand name or by monitor type, but strictly based on the resolution capabilities of the monitor. Continue to the monitor menu and select the resolution capabilities of the attached monitor.
2.Select the color depth and screen resolution on which the X Windows System will be run. You make this selection at the Modeselection screen. The selection settings on the screen will be limited by the abilities of the video card and the monitor. The screen resolutions are located in the center of the screen, and the color depth is located along the lower left part of the screen. Figure 4-25 shows the screen as it appears in the XFree86 setup program.