You first need to install the setserial utility which allows us to configure serial ports:
apt-get install setserial
Now we need to enter the /dev/ttyS0 (COM0) settings in /etc/serial.conf. Add this to the file:
/dev/ttyS0 port 0x220 irq 4 autoconfig
To apply the settings immediately, execute this command:
sudo /etc/init.d/setserial reload
Xorg Configuration
Add the following lines to /etc/X11/xorg.conf:
Section "Module"
...
Load "wacom" # add this line
EndSection
...
...
...
# These lines should go after the detected mouse and touchpad
Section "InputDevice"
Driver "wacom"
Identifier "cursor"
Option "Device" "/dev/ttyS0"
Option "ForceDevice" "ISDV4"
Option "Type" "cursor"
Option "Mode" "absolute"
Option "Speed" "3.0"
Option "Threshold" "2"
# Option "DebugLevel" "10"
# Option "MaxX" "24576"
# Option "MaxY" "18432"
EndSection
Section "InputDevice"
Driver "wacom"
Identifier "stylus"
Option "Device" "/dev/ttyS0"
Option "Type" "stylus"
Option "Mode" "absolute"
# Option "Tilt" "on"
# Option "TiltInvert" "on"
Option "Threshold" "2"
# Option "DebugLevel" "10"
EndSection
Section "InputDevice"
Driver "wacom"
Identifier "eraser"
Option "Device" "/dev/ttyS0"
Option "Type" "eraser"
Option "Mode" "absolute"
# Option "Tilt" "on"
# Option "TiltInvert" "on"
Option "Threshold" "2"
# Option "DebugLevel" "10"
EndSection
Section "ServerLayout"
...
# TabletPC Pen Device
InputDevice "cursor" "SendCoreEvents"
InputDevice "stylus" "SendCoreEvents"
InputDevice "eraser" "SendCoreEvents"
EndSection
Upon restarting X (sudo /etc/init.d/gdm restart), the tablet pc pen should work :)