Display

system-config-display

system-config-display is a graphical interface for configuring the X Window system display. This configuration tool generates the configuration file xorg.conf located under the /etc/X11/

folder. This tool can be used to setup, change, or reconfigure display settings. It is advised to save a copy of /etc/X11/xorg.conf before making any major changes.

Basic Usage

Basic Usage

To install the tool use the add remove applications utilities. If the system is connected to a "yum" channel, you can install the from the command line with " yum -y install system-config-display " command.

(For a larger image, click on the image (or click here))

You can access this application in the following ways:

• Computer ▸ Control Center ▸ Administration section ▸ Display
• From the command line, type: 'system-config-display &'
  • From the command line, type: 'system-config-display --reconfig' (to reconfigure X11)

System Resolution and Color Depth

Basic System Resolution and Color Depth

Dual Head (external monitor) Setup

Adding external monitors and docking stations

Advanced Reconfiguration Steps

Manually (re)configuring with system-config-display :

1. Boot system, either normally, or in single mode. If normally booted up, press Cntrl+alt+ F1 for a terminal prompt
   1. Login as root
   2. confirm your runlevel by typing runlevel
      (it should return somthing like "N 3" or "5 3" *key is that we want the right most number to be '3')
      (if the system is in runlevel 5 the system will automatically try to use the default settings, or it will fail and ask to reconfig "X".)
      (to continue with a manual reconfig follow the next steps.)
   3. if the runlevel is 5 change it with init 3 command
2. type the reconfig command

   system-config-display --reconfig

   
   (though, it is recommended that you first have a look at what xorg.conf files are located under /etc/X11 and back some/or all of them up)
3. After the tool has run, you should see a graphical screen. Do not configure the system at this point, restart X11 by typing init 5 or rebooting.
4. After logging in, adjust the display settings as needed. For the monitor, be sure to get the right settings
   (you can get the vert/horz rates from the back of the monitor)
   (if it's a laptop, pick "generic LCD" which can do your settings)
   

Troubleshooting

• The readily available Linux driver is invalid (and hence didn't detect it)
• You had picked the wrong monitor settings when configuring the monitors
• The monitor is simply very old and hence not 'plug and play'
• You don't have shared memory for video set in Bios (usually a problem for only certain desktops)
• The card is unique and may require an external tool such as aticonfig for ati cards.
  

Traditional Display Settings and Details

Traditional Display Settings and Details

This section describes in a more "traditional sense" the display settings in xorg.conf (the X-Window display config file). The meaning "traditional" infers that with time the xorg.conf file is containing less and less information and some system do not even have an xorg.conf file.

The following examples are taken from a basic xorg.conf configuration file and illustrate or explain the more important aspects of manually configuring a display. Note, these steps are for more advanced users who want to learn about how xorg.conf has been constructed.

• Example 1: The Server layout section of xorg.conf (this example was from a configured system in 2/2/2008)

  Section "ServerLayout"
         Identifier     "Multihead layout"
         Screen      0  "Screen0" LeftOf "Screen1"
         Screen      1  "Screen1" 0 0
         InputDevice    "Keyboard0" "CoreKeyboard"
         InputDevice    "Synaptics" "CorePointer"
         Option      "Xinerama" "off"
         Option      "Clone" "on"
  EndSection

  
  This section describes how many screens are connected to the system, which monitor is on the Left or right of the other, if the desk is to span across the two monitors or act as two seperate displays. In this case, there are two monitors called "multihead" with seperate desktops.
  

• Example 2: The Monitor section of xorg.conf (this example was from a configured system in 2/2/2008)

  Section "Monitor"
     "Monitor0"
      VendorName   "Monitor Vendor"
      ModelName    "Generic Monitor"
      HorizSync    30.0 - 69.0
      VertRefresh  50.0 - 120.0
      Option        "dpms"
  EndSection

  
  The Monitor section defines the display settings found on the back of the monitor. If you do not know the settings, pick a generic CRT or LCD monitor.
  

• Exampe 3: The Device driver section of xorg.conf (this example was from a configured system in 2/2/2008)

  Section "Device"
      Identifier  "Videocard0"
      Driver      "radeon"
      VendorName  "Videocard vendor"
      BoardName   "ATI Radeon Mobility 7500"
  EndSection

  
  The device section contains the actual driver used ( Radeon in this case ) and is the crucial for the video to work. Look up the proper driver for your video card.
  

• Example 4: The display size and color depth section of xorg.conf (this example was from a configured system in 2/2/2008)

  Section "Screen"
     Identifier "Screen0"
     Device     "Videocard0"
     Monitor    "Monitor0"
     DefaultDepth     16
     SubSection "Display"
          Viewport   0 0
          Depth     16
          Modes    "1280x1024"
     EndSubSection
     SubSection "Display"
          Viewport   0 0
          Depth     24
          "1400x1050"
     EndSubSection
  EndSection

  
  The screen section contains the resolution modes and color depth. The depth is usually 16bit or 24bit (which is 2^16 colors or 2^24 colors). Each depth has it's own Display subsection. The Defualt depth uses the display for that depth. In this example, the default is 16bit color and using the modes which starts with 1280x1024.
  
  

  Further Information

  Further Reading and Information

For more information regarding this tool, please refer to the following internal/external website(s):
http://www.redhat.com/docs/manuals/enterprise/