wahlau's online hut

today is great: i got a DELL 2001FP 20" TFT Monitor from the department!

the next challenge would be: how to get dual head working on my Ubuntu notebook? I don't recall having any software configuration tool where i can use to change my settings to dual head display (byte told me Fedora Core can do that with a GUI tool), nor there is a direct easy way to get it done... so next, down to the xorg.conf file.

there are some nice references online. Besides google, you can visit thinkwiki, wiki web for Thinkpad users in both windows and linux systems. From there i found some links to different how-tos that explain how one can get dual head to work. If you are searching for such info for your own hardware, be patience. It took me multiple xorg restarts, and different settings combinations from different sources before i finally got my thinkpad t43 to use dual head with wrong resolution :) The cool new 2001FP was displaying 640x480, talk about under-achievement :)

most important of all, please first make backup of your xorg.conf

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup.20050916

before you start editing xorg.conf, you must bear in mind that my settings is for IBM Thinkpad T43, model 1875. I will first list what is before, and what you should add in or modify:

for Section Device,

Section "Device"

Identifier      "Intel Corporation Intel Default Card"

Driver          "i810"

	Screen          0
	Option          "MonitorLayout"         "CRT, CRT+LFP"
BusID           "PCI:0:2:0"
EndSection
Section "Device"
	Identifier      "Card1"
	Driver          "i810"
	Screen          1
	Option          "MonitorLayout"         "CRT, CRT+LFP"
	BusID           "PCI:0:2:0"
EndSection

and for Section Monitor,

Section "Monitor"    

Identifier      "Generic Monitor"

Option          "DPMS"

HorizSync       28-49

VertRefresh     43-72

EndSection

Section "Monitor"
	Identifier   "MonExt"
	VendorName   "Dell"
	ModelName "Dell 2001FP (Digital)"
	Option      "DPMS"
	HorizSync 31.0-80.0
	VertRefresh 56.0-60.0
	DisplaySize 406 304
	Modeline    "1600x1200" 130.25 1600 1648 1680 1760 1200 1203 1207 1235
EndSection

now, Section Screen,

Section "Screen"

<long list skipped>

EndSection

Section "Screen"
	Identifier      "Screen1"
	Device          "Card1"
	Monitor         "MonExt"
	DefaultDepth    16
	SubSection "Display"
		Depth           16
		Modes           "1600x1200"
	EndSubSection
EndSection

as you can see, you only need to create a duplicate of Device, Monitor and Screen. I think til here, you have a rough feeling how to configure xorg yourself at a later time (perhaps to kill time, or as we always say, to optimize our configuration )

and last but not least, the ScreenLayout settings,

Section "ServerLayout"

Identifier     "DualHead"
	Screen         "Default Screen" LeftOf "Screen1"	
	Screen         "Screen1"
InputDevice     "Generic Keyboard"
InputDevice     "Configured Mouse"
InputDevice     "Synaptics Touchpad"
EndSection

the identifier field can be kept as it is, but i rather want to write it as DualHead, just to make sure i know why my settings looks slightly longer :)

one thing i learn: not all how-tos are 100% (copy and paste)-able. If you really want to make sure yours work, my advise is perseverence :) it is not difficult, since there are ready successful cases. But they might not be exactly the same settings as yours. So some observations and tweakings are necessary. For instance, pay attention to your TFT's specification. For 2001FP, in order to use 1600x1200, i must set the option VertRefresh to 56.0-60.0, because that is specified as default refresh rate at 1600x1200. anything higher would just not work.

to make sure life is easier, i have uploaded my xorg.conf here. download and compare yourself.

done! when you restart your xorg session, you should notice now you have display on both your LCD and TFT screen!

Note: if you wish to have Xinerama enabled, this how-to does not cover it yet :) i shall try it when i have time next week. What i did read is that you must have same resolution for both your TFT and LCD if you wish to use Xinerama. If that is true, then it is against the purpose why i wanted badly (yes, since i must convince my boss why i needed a 20" instead of a 17") a 20" TFT monitor - for its gorgeous 1600x1200, of course!

for more tweaks on T43, look for the nice how-to in thinkwiki.org.

have fun :)