Scott Granneman

Home Writing Presentations Teaching Web Dev Tech Info Useful Links Personal

Home > Tech Info > Linux > Installation > Dual Head HowTo

Linux Dual Head (AKA Monitor Spanning) HOWTO

I know that the following advice works on my setup, but it may not work on yours. Back up your X config file before tinkering with it!

Setup 1

IBM ThinkPad A31 laptop, running Kubuntu 5.04
AG Neovo F-419 monitor

The relevant portions of my laptop's /etc/X11/xorg.conf file that enables dual head (monitor spanning):

Section       "Device"
  Identifier  "ATI Technologies, Inc. Radeon Mobility 9000 (M7 LW)"
  Driver      "radeon"
  BusID       "PCI:1:0:0"
  Screen      0
EndSection

Section       "Device"
  Identifier  "ATI Technologies, Inc. Radeon Mobility 9000 (M7 LW) 2"
  Driver      "radeon"
  BusID       "PCI:1:0:0"
  Screen      1
EndSection

Section       "Monitor"
  Identifier  "Laptop Monitor"
  Option      "DPMS"
EndSection

Section       "Monitor"
  Identifier  "AG Neovo Monitor"
  VendorName  "AGNeovo"
  ModelName   "F-419"
  HorizSync   24-80
  VertRefresh 49-75
  Option      "DPMS"
EndSection

Section       "Screen"
  Identifier  "Laptop Screen"
  Device      "ATI Technologies, Inc. Radeon Mobility 9000 (M7 LW)"
  Monitor     "Laptop Monitor"
  DefaultDepth  24
  SubSection  "Display"
    Depth     1
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     4
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     8
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     15
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     16
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     24
    Modes     "1024x768"
  EndSubSection
EndSection

Section       "Screen"
  Identifier  "AG Neovo Screen"
  Device      "ATI Technologies, Inc. Radeon Mobility 9000 (M7 LW) 2"
  Monitor     "AG Neovo Monitor"
  DefaultDepth  24
  SubSection  "Display"
    Depth     1
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     4
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     8
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     15
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     16
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     24
    Modes     "1024x768"
  EndSubSection
EndSection

Section "ServerFlags"
  Option      "Xinerama"  "ON"
EndSection

Section "ServerLayout"
  Identifier  "Dual Head Layout"
  Screen      0 "Laptop Screen" 0 0
  Screen      1 "AG Neovo Screen" RightOf "Laptop Screen"
  InputDevice "Generic Keyboard"
  InputDevice "Configured Mouse"
  InputDevice "Synaptics Touchpad"
EndSection

Setup 2

IBM ThinkPad A31 laptop, running Kubuntu 7.04
Acer AL2216W 22" widescreen monitor

The relevant portions of my laptop's /etc/X11/xorg.conf file that enables dual head (monitor spanning):

Section "Device"
        Identifier      "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
        Driver          "ati"
        BusID           "PCI:1:0:0"
        Screen          0
EndSection

Section "Device"
        Identifier      "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500] 2"
        Driver          "ati"
        BusID           "PCI:1:0:0"
        Screen          1
EndSection

Section "Monitor"
        Identifier      "Laptop Monitor"
        Option          "DPMS"
EndSection

Section       "Monitor"
  Identifier  "Acer Monitor"
  VendorName  "Acer"
  ModelName   "AL2216W"
  HorizSync   30-82
  VertRefresh 56-76
  Option      "DPMS"
EndSection

Section "Screen"
        Identifier      "Laptop Screen"
        Device          "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
        Monitor         "Laptop Monitor"
        DefaultDepth    24
        SubSection "Display"
                Depth           1
                Modes           "1024x768"
        EndSubSection
        SubSection "Display"
                Depth           4
                Modes           "1024x768"
        EndSubSection
        SubSection "Display"
                Depth           8
                Modes           "1024x768"
        EndSubSection
        SubSection "Display"
                Depth           15
                Modes           "1024x768"
        EndSubSection
        SubSection "Display"
                Depth           16
                Modes           "1024x768"
        EndSubSection
        SubSection "Display"
                Depth           24
                Modes           "1024x768"
        EndSubSection
EndSection

Section       "Screen"
  Identifier  "Acer Screen"
  Device      "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500] 2"
  Monitor     "Acer Monitor"
  DefaultDepth  24
  SubSection  "Display"
    Depth     1
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     4
    Modes     "1024x768"
  EndSubSection
  SubSection  "Display"
    Depth     8
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     15
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     16
    Modes     "1024x768"
  EndSubSection
  SubSection "Display"
    Depth     24
    Modes     "1680x1050" "1024x768"
  EndSubSection
EndSection

Section "ServerFlags"
  Option      "Xinerama"  "ON"
EndSection

Section "ServerLayout"
        Identifier      "Dual Head Layout"
        Screen          0 "Laptop Screen" 0 0
        Screen          1 "Acer Screen" RightOf "Laptop Screen"
        InputDevice     "Generic Keyboard"
        InputDevice     "Configured Mouse"
        InputDevice     "stylus"        "SendCoreEvents"
        InputDevice     "cursor"        "SendCoreEvents"
        InputDevice     "eraser"        "SendCoreEvents"
        InputDevice     "Synaptics Touchpad"
EndSection

The upshot

The best part: when I boot the laptop & it's not connected to the AG Neovo monitor, the laptop detects that & displays everythong on the laptop's monitor. Excellent.