LitepadFix

[This project page was resurrected from a 2005 archive]

Many NEC Litepad TabletPCs have a ‘crazy cursor’ hardware bug which causes the pen/cursor to move to and click at the top right hand corner of the screen (in Portrait mode) or the button right hand corner of the screen (in Landscape mode). This can cause the tablet to randomly close windows or open up the Date and Time dialog box. Very annoying!

All Tablet PCs use electromagnetic digitizers for input (instead of touch panel based input) and the source of this bug appears to be related to the lack of sufficient electromagnetic shielding. Some users find that the bug occurs at certain physical locations (like at work or at home) more than at other locations.

If you are still under warranty, a replacement motherboard from NEC may be able to fix the issue but users have reported that after a period of time, the problem reoccurs.

LitePadFix is a small software based fix for the ‘crazy cursor’. The program filters out sudden cursor jumps to the top right hand corner of the screen (in Portrait mode) and to the bottom right hand corner of the screen (in Landscape mode). It should eliminate most, if not all, unwanted ‘crazy cursor’ clicks and jumps.

 Installation

Download this zip file then extract and run the setup exe file inside.  If you have anti-spyware software installed, you may get a warning about LitepadFix installing itself into the startup sequence of windows.  Please allow this action.  If you block the action then LitepadFix won’t automatically start when you start windows and you will have to manually run it every time you login.

For those who want to know, LitepadFix adds itself to the HKLM\Software\Microsoft\Windows\CurrentVersion\Run registry key.

Uninstallation

Go to Add/Remove programs in Control Panel.  LitepadFix will be listed under the name “LitepadFix”.

Limitations

Closing Windows

Pen based computing is different from mouse based computing in that if you want to move your cursor from location A to location B, you can do it instantly without the cursor having to travel through points in the space between A and B. If you try to close a maximized window by instantaneously moving to the top right hand corner of the screen (by raising your pen over 2cm above the screen when moving) LitepadFix will detect this as a ‘crazy cursor’ movement and filter it out. In order to close a maximized window should move your pen above the screen (no more than 1cm above so that the digitizer can detect it) and move the cursor towards the top right hand corner of the screen in a continuous motion as you would with a mouse. Most people will find that this already is how they close windows on a Tablet PC.

Screen Orientation

Litepad displays can be (software) oriented in all four directions. LitepadFix will only work in two directions: Normal portrait mode (Litepad right side up) and normal landscape mode (Litepad rotated clockwise 90 degrees). These are usually the only orientations people work with as the other two orientations aren’t hardware accelerated and are *VERY* slow. Besides, Litepads are so thin and light that it’s faster to just physically reorient a tablet when demonstrating to people :-).

Operation

LitepadFix starts quietly in the background and adds an icon to the system tray whenever you login.  You can identify what the icon looks like from the following screenshot:

If for any reason you want to close LitepadFix, right click on the system tray icon and select “Exit”.  If you don’t want the LitePadFix icon showing up on the system tray (this is usually the case since tablets have very limited taskbar real-estate), use the taskbar “inactive icons” feature inbuilt into XP.

You can test to see if LitepadFix is working by moving your cursor to the bottom left hand corner of the screen, raising your pen away from the screen and then bringing the pen down onto the top right hand corner of the screen.  If LitepadFix is working then you will find that the cursor remains at the bottom of the screen and won’t move to the top right hand corner of the screen.  Try moving your pen (hovering less than 1cm above the screen) in a steady continuous motion from the bottom left of the screen to the top right.  You should find that, this time, the cursor will follow the pen and move all the way to the top right hand corner of the screen.

Requirements

• Windows XP Tablet PC edition (.NET not required)

Donations

Litepad is free.  If you find it useful, please make a donation: