(from Lee Monamy)
Example XF86Config-4 for an ELO touch screen:
Section "InputDevice"
Identifier "ELO touchscreen"
Driver "elographics"
Option "Device" "/dev/ttyS0"
Option "MinimumXPosition" "300"
Option "MaximumXPosition" "3700"
Option "MinimumYPosition" "300"
Option "MaximumYPosition" "3700"
Option "UntouchDelay" "10"
Option "ReportDelay" "10"
Option "SendCoreEvents" "yes"
EndSection
Noteable differences between this and the version 3 config are that you specify a Device, *not* a Port, otherwise you get an error. Also, AlwaysCore from v3 has been replaced with SendCoreEvents.
You must also add to the ServerLayout section, despite that X might say: "(II) XINPUT: Adding extended input device "TOUCHSCREEN" (type: Elographics Touch Screen)"
Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
...
InputDevice "ELO touchscreen"
EndSection
from Dirk Mueller (for Microtouch SMT3 Series):
Section "InputDevice"
Identifier "MicroTouchFinger"
Driver "mutouch"
Option "Type" "finger"
Option "Device" "/dev/ttyS0"
Option "ScreenNo" "0"
Option "MinimumXPosition" "0"
Option "MaximumXPosition" "16383"
Option "MinimumYPosition" "0"
Option "MaximumYPosition" "16383"
EndSection
Option "Type" can be "finger" or "stylus" Since Microtouch was bought by 3M-Touch, the resources are on http://www.3M.com/3MTouchSystems/downloads/legacy.jhtml#Linux
According to Wong Yeow Sen the configuration option names have changed in XFree86 4.2 (at least with Red Hat 7.3). If it seems your calibration values aren't parsed try the following:
...
Option "MinX" "100"
Option "MaxX" "4000"
Option "MinY" "100"
Option "MaxY" "4000"
...