X Windows System Configuration

Background

Unlike MS-Windows, Linux's Window System does not take the generic names like "door" or "gate" :-) and posses it. It has a cute name like: X (i.e. X Window System). X was developed in MIT. X is not tangled in the kernel. Therefore, a Linux does not have to be configured with X window system. This is ideal for a server which does not require fancy GUI tools. Linux, however, is normally configured with X. Under X, the server is running on the local machine, there rest of tools related to X are named Xclients including window manger. A window manager is capable of resizing, iconifying other Xclients and create virtual desktop.

Configuration

X server is nothing but a utility (or application) on top of the kernel, it reads a configuration file about the system's hardware. This could be one of the most difficult areas for installing Linux due to many different video cards (chipset), and monitors configured with PCs.

XF86Setup/Xconfigurator: for generating an X server configuration file named XF86Config.

/usr/lib/X11R6/lib/X11/XF86Config (which points to /etc/X11/XF86Config)
/root/XF86Config - when starting X server via a shell command named startx as root

XF86Setup is a GUI tool for selecting the video adaptor, monitor resolution, keyboard and mouse. To run XF86Setup, it requires a generic X server named XF86_VGA16. One should gather as much information for the brand (chipset) of video adaptor, and monitor. The information may be obtained from the device driver (control panel -> system) section under Win9[58].
Configuration Steps:
If you do not have the information of your video card, you may use Xconfigurator to get it, then switch to XF86Setup to proceed the X configuration.

Login as root

Enter Xconfigurator and select Ok: write down the chipsset and X server information. Use tab key to move to press on Back button -> Cancel to quit.

Enter XF86Setup: which is stored under /usr/X11R6/bin
RedHat 6.1 does not install VGA server nor XF86Setup by default. To install VGA server and XF86Setup:
mount /dev/cdrom /cdrom
cd /cdrom/RedHat/RPMS
rpm -i *-VGA*
rpm -i *XF86Setup*
If you cannot mount the CD-ROM under Linux and if happen to have Win9[58] on the the same system, you may boot Win9[58] to copy *-VGA* and *XF86Set* to hard drive (e.g. under c:\tmp). You then reboot the system to Linux, for accessing those two packages.
mount /dev/hda1 /mnt
cd /mnt/tmp
rpm -i *-VGA*
rpm -i *XF86Setup*

Click on No twice on the 1_st and 2_nd screen

Click on Ok and bring up a screen with the following buttons on the top: Mouse, Card, Monitor, ModeSelection and other.

Click on Mouse for selecting mouse device: default ps/2 which is the most popular one.

Click on Card for selecting video adaptor: this is critical and make sure to pick the correct one from the information gathered.

Click on Monitor for selecting resolution: this is where you need to be patient for try and errors.

Click on ModeSelection for selecting the matched resolution and color depth (try 8-bit first, if you don't know.)

Click on Done, Okay and wait. If the screen comes up with an "X", you are getting there. You will see a few buttons, simply click on Save the configuration and exit button. If you see some error messges, press < ctrl > C to quit. If you don't see any error messges nor an "X", you need to press < ctrl > < Alt > < Backspace > to terminate X server. You have to restart XF86Setup to try different resolution until you find a working version which may be the worst resolution. In the worst case, you may have to search the web to download a XF86Config file that is closer to your system's chipset and work from there.

Enter startx: this brings up X server and Gnome desktop.

Note: One should copy important configuration files (such as XF86Config) onto a MS-DOS floppy via
mcopy XF86Config a:
or
tar cvf /dev/fd0 XF86Config or
mount -t msdos /dev/fd0 /mnt; cp XF86Config /mnt
To restore it back to /tmp, enter:
cd /tmp; mcopy a:
or
cd /tmp; tar xvf /dev/fd0.

If X server doesn't paint the screen properly, one may use xvidtune for tuning. Xvidtune contains buttons such as left, right, up, down, taller, shorter, wider, narrower, auto and show. After obtaining the best layout, press show button to show the horizontal and vertical refresh rate. (number of times a second the monitor can display a horizontal line and the entire screen respectively.) Note: backup a copy of XF86Config under /etc/X11 or /etc before using an editor for making any modifications.
To increase the screen resolution, go to Section "screen" in XF86Config, you will see Subsection "Display" which has an entry for Modes "600x480". It can be replaced as
Modes "1024x768" "800x600" "640x480"
X server will try different resolution based upon the above order. Be sure that all the modes have been defined in the same file under the "Monitor" section. It typically looks like the following line:
"Modeline "800x600" 28.32 800 816 856 920 600 603 605 618

Once you are satisfied with the size of a screen via xvidtune, you should make adjustments to the above entry. (Press 'Apply' button for any changes. Press 'Show' button will show the correct refresh rates for 'Modeline' on the xterm window.) When upgrading X server, simply save the old X server(i.e. /usr/X11R6/bin/XF86_YourDispaly) and install new one.
xfs: font server which supplies fonts to Xserver either locally or remotely. You may locate the font server configuration file under /usr/X11R6/lib/X11/fs/config. Make sure 'FontPath' points to the correct directory. All the font directories contain a file named fonts.dir which is updated by "mkfontdir" command. One of the most important font which has an alias name "fixed" is under: /usr/X11R6/lib/X11/fonts/misc/.
X will fail if it cannot locate this font. Xfs normally started via a script named xfs under /etc/rc.d/init.d. If you are not running xfs or it fails (try ps aux|grep xfs), you should comment out (adding # in the front of first word) the line that has FontPath points to nowhere and add new FontPath in XF86Config. I.e.:
```
    #FontPath   "unix/:-1"
    FontPath    "/usr/X11R6/lib/X11/fonts/misc/"
    FontPath    "/usr/X11R6/lib/X11/fonts/Type1/"
    FontPath    "/usr/X11R6/lib/X11/fonts/Speedo/"
    FontPath    "/usr/X11R6/lib/X11/fonts/75dpi/"
```
Adding new fonts such as /usr/X11R6/lib/X11/fonts/misc/{cns-1-24.pcf,cns-2-24.pcf} requires to update directory information via command mkfontdir /usr/X11R6/lib/X11/fonts/misc. These two fonts are used in netscape to display Big5 coding. There are other Big5 fonts under this web site. To refresh newly added fonts information, enter xset f rehash or restart X.
xdm/kdm: Configuration files - /usr/X11R6/lib/X11/xdm
Xdm manages a collection of X displays, which may be on the local host or remote servers. It provides GUI login feature.
startx -> xinit -> X server: it reads the entries in $HOME/.xinitrc to start up Xclients. If X fails to come up, try to run startx >& /tmp/x.out Study x.out or post questions on the net or visit Linux Search for answers.
X hindow managers: which is capable of manipulating windows on the root window. Most popular ones are: twm, fvwm, enlightenment and etc.
xrsh: a handy shell script to start Xclients remotely. ($HOME/.rhosts needs to have entry for the X server's hostname)

X clients attributes: X is very flexible. One can customize the display attributes as a whole and individually. Attributes typically set by individual files under /usr/X11R6/lib/X11/app-defaults. They can also be overridden by xrdb command with an input file contains information for widget class and attribute. E.g.:

xrdb $HOME/.xrdb
$HOME/.xrdb:

!
! my vt100 xterm short cuts
!
vt100*VT100.Translations: #override \
 F4: string("setenv DISPLAY 204.146.56.118:0") string("0xd") \n\
 F7: string("anonymous") string("0xd") \n\
 F8: string("klai@home.net") string("0xd") \n\
 F12: string("exit") string("0xd")
! Emacs 
Emacs*Font:                    lucidasanstypewriter-bold-14


e.g.: Running an xterm session with designated font and geometry.

xterm -fn 9x15 -g 80x24-0-0

X Desktop: kde, gnome, xfce, Miscellaneous.
To customize "enlightenment", the window manager under Gnome, click on tool box near the bottom of task bar and select "Window Manager" under Desktop. You may select "Sloppy pointer" for keyboard focus vs. the default "Mouse pointer" style adopted by Win9[58]. You may add or reduce the number of desktops to give you a freedom of the virtual windows. Additionally, you may define short cuts such as swapping keys, assigning function keys for jumping between different desktop, and raisinglowering windows with single keystroke.

References: