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Troubleshooting
display is powered off. Internal serial controllers are usually powered by a supply
that is separate from the display's power supply, but controlled through the
display's power switch. In this case, even if display problems exist, the
touchscreen system will probably function if the display power switch is on.
Peeling Back the Layers
The secret to troubleshooting is to first identify at what level the problem exists.
For example, if your application uses MonitorMouse for DOS, there are several
layers of software and drivers involved. The problem could be with your
application, MonitorMouse for DOS, ELODEV, your mouse driver, the
touchscreen hardware, or a conflict with other software. The problem could even
be at a lower level such as a conflict with other hardware, or even the computer.
The best approach to troubleshooting is to remove the layers one by one until the
problem disappears. If the problem exists after all software has been removed,
then hardware troubleshooting is in order.
Calibration Problems
Calibration problems can appear at any level. If the touchscreen hardware is
responding and is linear, (see COMDUMP, BUSSTAT, and TOUCHES later in
this appendix), but a touch does not activate the appropriate zone, check the
calibration. Other symptoms of improper calibration are when a cursor does not
move at the same pace as a sliding finger, or when it moves in the opposite
direction. A cursor should always move in the same axis as your finger.
Calibration problems are usually due to calibrating in the wrong video mode.
Even though you may have a VGA monitor, for example, your application may be
running in text mode, so calibrate in text mode rather than graphics mode.
If using MonitorMouse for DOS with a DOS application, apparent calibration
problems may actually be due to a relative mode application. See Coordinates vs.
Mickeys, page 42, and MonitorMouse for DOS later in this appendix for help on
identifying this situation.
If you have a calibration problem, try erasing ELOGRAPH.CAL and re-running
DEMOCAL or ELOCALIB. Only ELODEMO and MonitorMouse for DOS use
ELOGRAPH.CAL. TouchBack does not.
Besides the remainder of this appendix, see the following sections for more
information on calibration:
