On 07/06/2011 03:06 AM, g wrote:
<>
there are ir leds emitting at surface of balls and ir detectors
receiving
reflections from ball surface.
in addition, there are some trackball mice that use a roller bar, ie, like
a standard mouse. i do not recommend them. they do not track well.
you will also find 'palm ball' types, but they are not as convent to use
as a 'thumb ball'. i had one and gave it away.
--
peace out.
tc.hago,
g
.