Dual Head

Dual Head on IBM T43 running Ubuntu

Related configuration in /etc/X11/xorg.conf:

Section "Device"
	Identifier	"d0"
	Driver		"ati"
	BusID		"PCI:1:0:0"
	Screen          0
EndSection

Section "Device"
	Identifier	"d1"
	Driver		"ati"
	BusID		"PCI:1:0:0"
	Screen          1
EndSection

Section "Monitor"
	Identifier	"m0"
	Option		"DPMS"
EndSection

Section "Monitor"
	Identifier	"m1"
	Option		"DPMS"
	Modeline "1440x900" 106.5 1440 1520 1672 1904 900 903 909 934
EndSection

Section "Monitor"
	Identifier	"m2"
	Option		"DPMS"
EndSection

Section "Screen"
	Identifier	"s0"
	Device		"d0"
	Monitor		"m0"
	DefaultDepth	24
	SubSection "Display"
		Depth		24
		Modes		"1024x768"
	EndSubSection
EndSection

Section "Screen"
	Identifier	"s1"
	Device		"d1"
	Monitor		"m1"
	DefaultDepth	24
	SubSection "Display"
		Depth		24
		Modes		"1440x900"
	EndSubSection
EndSection

Section "Screen"
	Identifier	"s2"
	Device		"d1"
	Monitor		"m2"
	DefaultDepth	24
	SubSection "Display"
		Depth		24
		Modes		"1024x768"
	EndSubSection
EndSection


Section "ServerLayout"
	Identifier	"Dual2"
	Screen		0 "s0" 0 0
	Screen		1 "s2" Above "s0"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice	"Synaptics Touchpad"
	Option "Xinerama" "true"
	Option "Clone" "on"
EndSection

Section "ServerLayout"
	Identifier	"Dual"
	Screen		0 "s0" 0 0
	Screen		1 "s1" Above "s0"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice	"Synaptics Touchpad"
	Option "Xinerama" "true"
	Option "Clone" "on"
EndSection

Section "ServerLayout"
	Identifier	"Single"
	Screen		"s0"
	InputDevice	"Generic Keyboard"
	InputDevice	"Configured Mouse"
	InputDevice	"Synaptics Touchpad"
EndSection

I do not need Dual head always, and I have two different monitor types in use: 1440x900 and 1024x768. So I have 3 different X servers running. Related /etc/gdm/gdm.conf:

[servers]
0=Standard
1=Dualhead
2=Dualhead2

# Definition of the standard X server.
[server-Standard]
name=Standard server
command=/usr/X11R6/bin/X -br -audit 0 -layout "Single"
flexible=true

# Definition of the Dual head X server with 1440x900 resolution
[server-Dualhead]
name=Dualhead server
command=/usr/X11R6/bin/X -br -audit 0 -layout "Dual"
flexible=true

# Definition of the Dual head X server with 1024x768 resolution
[server-Dualhead2]
name=Dualhead server
command=/usr/X11R6/bin/X -br -audit 0 -layout "Dual2"
flexible=true