June 2005
Over time it was thought that having a lot of hardware was great. As time has moved on the thought has become less hardware that can do more and elegantly. With extended desktops under X windows using Xinerama, that can be achieved.
Sometimes in X windows, we all want to try something strange. It is in the nature of the curious OS user to do. A look at extending a laptop display using xinerama and x.org.
The hardware is probably considered marginal by most of the l33t community [ 1 ] but it makes for the best (or worst depending on your point of view) case example. Following is the laptop involved:
processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 13 model name : Intel(R) Celeron(R) M processor 1.30GHz stepping : 6 cpu MHz : 1299.342 cache size : 1024 KB ... MemTotal : 498008 kB ... Filesystem 1K-blocks Used Available /dev/hda 237122736 16415460 18791124 ...
Outside of the above, it uses USB for _all_ keyboard and mice operations which made life a bit easier. All that had to be done was to switch on USB core support for mice and keyboards (more on that later).
So, there is a single Acer 1410 laptop with X.org running just fine using framebuffer in console and for X (the needs for graphics - at the time - were limited). Now it has to be able to extend out to at least a 1024x768 with 16bpp+ monitor.
How can it be done?
In truth, the answer was two parts. Using xinerama and updating to the latest x.org release. The system in question uses slackware-10 base so moving over the installed X was not a big deal.
Anyone who does anything different is a complete moron. If there is not
space then find a way to backup the current working X directory whether
it is a simple cd /usr; cp -Rp X11R6 X11R6.orig or
streaming it off to /dev/st0. [ 2 ]
xorg.conf FileAll that is needed is a working config file. Next are some pictures of it in action.
Section "ServerLayout"
Identifier "Xinerama Layout"
Screen "Screen0"
Screen "Screen1" RightOf "Screen0"
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection
Section "ServerFlags"
Option "Xinerama" "true"
EndSection
Section "Files"
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "/usr/X11R6/lib/X11/fonts/local/"
FontPath "/usr/X11R6/lib/X11/fonts/misc/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/Type1/"
FontPath "/usr/X11R6/lib/X11/fonts/CID/"
FontPath "/usr/X11R6/lib/X11/fonts/Speedo/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi/"
FontPath "/usr/X11R6/lib/X11/fonts/cyrillic/"
EndSection
Section "Module"
Load "dbe" # Double buffer extension
Load "extmod"
SubSection "extmod"
Option "omit xfree86-dga" # don't initialise the DGA extension
EndSubSection
Load "type1"
Load "freetype"
# Load "speedo"
Load "glx"
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "keyboard"
EndSection
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "ExplorerPS/2"
Option "ZAxisMapping" "6 7"
Option "ButtonNumber" "7"
Option "Buttons" "7"
Option "Device" "/dev/mouse"
EndSection
Section "Monitor"
Identifier "LCD
VendorName "Acer LFP LCD"
Identifier "LCD
VendorName "Acer LFP LCD"
ModelName "LCD Panel 1024x768"
DisplaySize 320 240
HorizSync 31.5 - 48.5
VertRefresh 40.0 - 70.0
Option "dpms"
EndSection
Section "Monitor"
Identifier "CRT"
VendorName "Dell"
ModelName "CRT Screen 1280x1024"
DisplaySize 320 240
HorizSync 31.5 - 48.5
VertRefresh 40.0 - 70.0
Option "dpms"
EndSection
Section "Device"
Identifier "i855a"
Driver "i810"
VendorName "Videocard vendor"
BoardName "Intel 852"
BusId "0:2:0"
Option "Clone" "false"
#Option "DevicePresence" "false"
#Option "FlipPrimary" "true"
Option "DRI" "true"
#Option "CloneRefresh" "75"
Option "MonitorLayout" "CRT,LFP"
Screen 0
EndSection
Section "Device"
Identifier "i855b"
Driver "i810"
VendorName "Videocard vendor"
BoardName "Intel 852"
BusId "0:2:0"
Screen 1
EndSection
Section "Screen"
Identifier "Screen0"
Device "i855a"
Monitor "LCD"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 16
Modes "800x600" "640x480"
EndSubSection
SubSection "Display"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1024x768" "800x600" "640x480"
EndSubSection
EndSection
Section "Screen"
Identifier "Screen1"
Device "i855b"
Monitor "CRT"
DefaultDepth 24
SubSection "Display"
Viewport 0 0
Depth 16
Modes "800x600" "640x480"
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 24
Modes "1024x768" "800x600" "640x480"
EndSubSection
EndSection
Section "DRI"
Group 0
Mode 0666
EndSection
Note it works with the 855{G}M intel video card but it uses
the i810 driver, the i810 driver holds true for many
of the laptop displays out there.
Now at long last, some imagery from the setup. First, the actual physical area. In the picture, there is a laptop and an 8-cube TFT that is using the same video bus as the laptop screen.
Here is a screenshot in action using e17 across two 1024x768's under the extended desktop scenario.
Getting the desktop to a point where it is usable whether that is ergonomically, visibly or even artistically is fun, something we could all use a little more of.
(based on last 2 months log reports)
