[plug] Touch Screens

[Denis Brown]

Hello, Garth.

This is an off-list reply because I have had some experience with IBM touch 
screens but not in combination with Linux.  I wrote an assembly-language 
driver to interface with some psychological test programmes a loooong time 
ago and am not even sure if I still have the source code!

The IBM screen came with a "glass mouse" programme and required resident 
code which at boot time, uploaded microcode to the monitor/touch 
electronics.  Very complex in the usual IBM way but also very slick.  This 
breed could give you a Z axis to something like 256 levels of force!  They 
used four strain gauges, one at each corner of the screen.  Of course it 
also needed a calibration programme.  The model is now obsolete and has 
been replaced with something akin to the Carroll Touch and other capacitive 
technology screens.

If you get lucky, there might be a touch screen how-to?  If you think I can 
be of assistance please let me know.

Cheers,
Denis