Re: something weird on Linux 2.4.17 on an IBM Thinkpad T20

[Andreas Dilger <adilger@clusterfs.com>]

On Apr 19, 2002  09:17 +0900, Adrian V. Bono wrote:
> While working in X on kernel 2.4.17 on an IBM Thinkpad T20, sometimes 
> the mouse pointer would just gravitate all by itself, without my moving 
> the mouse or pointing stick, upwards. The first time that happened, i 
> was coding in an xterm when suddenly, window focus shifted to another 
> window and i noticed the mouse pointer was moving upwards by itself. 
> Anyone else notice this?

This is common to all thinkpads (or other laptops which have trackpoint
devices) and also happens under Windows.  The cause is related to
automatic compensation for the centering of the trackpoint.  Early
trackpoint devices didn't have automatic centering and I remember
replacing more than a few keyboards because the mouse would start
drifting by itself.  Later trackpoints have automatic centering, but
if you hold onto the trackpoint for a long time (causing the "center"
to be offset by some amount) and then let go, it will settle back to
the "old center" and the cursor will drift for a few seconds until
the automatic centering kicks in again.

Moral of the story - don't touch the trackpoint when you aren't doing
anything with it.

Cheers, Andreas
--
Andreas Dilger
http://www-mddsp.enel.ucalgary.ca/People/adilger/
http://sourceforge.net/projects/ext2resize/