Manual resolution setting not affecting touchscreen

I have customer who is using a display with a touchscreen with an older version of Slackware, version 12.2. Slackware is not recognizing the resolution of the display, 1600x1200. Going into the display settings the resolution was listed. They are using a GeForce 9800GT and ran the the Nvidia drivers to create a new config. They went in manually and added the resolution to the xorg.conf file. This has allowed the resolution to be displayed at 1600x1200, but the touchscreen does not appear to be operating at that resolution. It appears to be working off a different resolution. So if I touch around the edges of the touchscreen it makes a smaller box than the screen. We have been able to duplicate this problem on a test rig, but we don't have anyone well versed in linux. After talking to the touchscreen manufacturer, they say that it is not an issue with their linux drivers, it works with Slackware.

This is the section added to the xorg.conf file:
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
Viewport 0 0
Modes "1600x1200"
EndSubSection
EndSection

Should modifying the xorg.conf like this let it work or is a different approach required? I am not sure if I should try to work with what they are doing or if we need to go in a different direction.

Right now I'm not on my laptop with a touchscreen, but I remember that I had a similar problem when the touch screen synced to the external monitor rather than the actual touch screen. The point is that the touch screen is more like a wacom tablet laid over the monitor. So you have to use

xsetwacom

to scale the touch screen to your actual monitor.

I can look up the exact commands tomorrow if it is still needed, but searching the internet for the exact xsetwacom command should help.

It looks like this command is specific for Wacom touchscreens. This command is not found when I tried it so I don't have that installed. Is it part of drivers that aren't specific to Wacom as well? I forgot to mention the manufacturer of the touchscreen in my original post. It is 3M.

Originally Posted by mkdigital It looks like this command is specific for Wacom touchscreens. This command is not found when I tried it so I don't have that installed. Is it part of drivers that aren't specific to Wacom as well? I forgot to mention the manufacturer of the touchscreen in my original post. It is 3M.

I thought I used this tool on non-wacom devices in the past, but I might be wrong. I'm now on my touch device and realized that I moved the calibration configuration to a xorg.conf file:

# cat /etc/X11/xorg.conf.d/99-calibration.conf 
Section "InputClass"
	Identifier	"calibration"
	MatchProduct	"Wacom ISDv4 E6 Pen"
	Option "ForceDevice" "LVDS1"
	Option	"MinX"	"120"
	Option	"MaxX"	"27609"
	Option	"MinY"	"-44"
	Option	"MaxY"	"15512"
EndSection

Something along those lines might work for you, too. Of course the numbers and the product name will be different for you. You should be able to find the product name using

xinput --list

but I guess you already know this. The "ForceDevice" line is important if you attach other monitors to make sure it calibrates with respect to the monitor which is actually behind the touch sensor.