Dualhead Clone On The Thinkpad R51

I have been trying to switch over to just using my laptop for all my computer usage, but don’t want to throw down the money for a dock station unless I am sure. The biggest issue I have been having is setting up the vga out on the laptop to clone the current desktop that is running at 1024×768 to the 1440×900 wide screen lcd. To sum that up I want to clone the desktop not only to a larger resolution, but also change the aspect.

Here are the random snippets of interest that I added to my xorg.conf. This is not the full xorg.conf and only shows the sections related to video and display setup.

Section "Device"
	Identifier	"card2"
#	Driver		"ati"
	Driver		"radeon"
	BusID		"PCI:1:0:0"
	Screen 0
        #Option "MonitorLayout" "CRT,LFP"
        Option "Clone" "true"
	#Option 		"CloneMode" "1440x900"
EndSection

Section "Device"
	Identifier	"card1"
	Driver		"radeon"
#	Driver		"ati"
	BusID		"PCI:1:0:0"
	Screen 1
        #Option "MonitorLayout" "CRT,LFP"
        Option "Clone" "true"
	#Option 		"CloneMode" "1440x900"
EndSection

Section "Monitor"
	Identifier	"Generic Monitor"
	Option		"DPMS"
EndSection

Section "Monitor"
	Identifier	"Generic Monitor 2"
	HorizSync 30-82
	VertRefresh 56-76
	Option		"DPMS"
EndSection

Section "Screen"
	Identifier "Default Screen 2"
	Device	"card2"
#	Device	"card1"
	DefaultDepth	24
	Monitor	"Generic Monitor 2"
	SubSection "Display"
		Depth	24
		Modes	"1440x900"
	EndSubSection
EndSection

Section "Screen"
	Identifier	"Default Screen"
	Device		"card1"
	Monitor		"Generic 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 "ServerLayout"
	Identifier	"Default Layout"
	Screen		"Default Screen"
	Screen		"Default Screen 2" #LeftOf "Default Screen"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice     "stylus"	"SendCoreEvents"
	InputDevice     "cursor"	"SendCoreEvents"
	InputDevice     "eraser"	"SendCoreEvents"
	InputDevice	"Synaptics Touchpad"
	Option "Xinerama" "on"
#	Option "Clone" "1"
EndSection

After some playing around in the xorg.conf file I was able to get something close to what I wanted, but it is a little buggy as you will see below.

I normally don’t have the bottom panel there so for the most part it works (Putting the bottom panel in lets you see what is going on better). As you can see from the image gnome is thinking that it is still running in 1024×768. Both Gnome and xfce do the same placement of the panels. Cloning is working but a little buggy. :)

This image shows that the applications will actually function in the space between the panels.

Maximize actually will only fit the window between the two panels in the 1024×768 area. If the window is outside the 1024×768 area it will maximize to the full screen of 1440×900.

This is the part of the post where it starts to get interesting. If we actually remove the bottom panel (how I normally have my desktop setup) and use the maximize, the window will actually goto the full screen and you can also see that even with both panels the whole area of the 1440×900 area is usable. Maximize when both panels are on will also go full if the window is larger than the 1024×768 area. With removing the bottom panel the desktop starts to seem more usable.

Actually looking at the laptop screen while using the other monitor you can see that stuff is just going off the display area of the smaller display but can be seen on the larger widescreen lcd. For some reason it looks like xorg understands that the extra area is on the other monitor and is using all the space. Gnome, xfce, and gdm don’t seem to understand what is going on and stay true to the laptops lcd’s .

One of the more confusing things for me is that the background manager (gnome) will actually scale the background image to the correct size on both lcds. I don’t know enough about how gnome is placing the panels or figuring out the size of windows, but maybe it needs to be thinking of it as percents so that it can change dynamically with the screen size?