Hardware Reference
In-Depth Information
I have compared the TrackPoint device to other pointing devices for laptops (especially
touch pads), but nothing compares in terms of accuracy and control—and, of course, the
fact that you don't have to take your hands off the keyboard to use it!
Unfortunately, most of the TrackPoint devices used by laptops other than IBM/Lenovo
don't have the full features of the IBM/Lenovo versions, especially including the multiple
tip choices, the third scroll button, and “negative inertia” control. One important feature
to look for is the ability to accept different IBM/Lenovo TrackPoint caps. These have a
square hole in them and allow choosing from several different types.
Over the years IBM/Lenovo has upgraded the TrackPoint pointing stick to the TrackPoint
III and the current TrackPoint IV. Two main differences exist in the III/IV system, but the
most obvious one is the rubber cap. The original caps were made from pure silicone rub-
ber,whichwasgrippyandworkedwellinmostsituations.However,iftheuserhasgreasy
fingers, the textured surface of the rubber can become slippery. Cleaning the cap (and the
user's hands) solves the problem, but it can be annoying at times. The TrackPoint III and
later standard caps are made from a different type of rubber, which Selker calls “plastic
sandpaper.”Thistypeofcapismuchmoregrippyanddoesnotrequirecleaningexceptfor
cosmetic purposes. More recently IBM/Lenovo introduced other caps that do not feature
the sandpaper surface, but have either a wider soft dome or a wider concave surface for
additional grip. IBM/Lenovo now has three types of caps for the TrackPoint to suit differ-
ent needs and tastes. These different caps are interchangeable with the older styles as well
(see
Figure 15.13
):
•
Classic dome (P/N 84G6537)
—The traditional “pencil eraser” cap with a sandpaper
surface.
•
Soft rim (P/N 91P8423)
—A larger concave nonsandpaper design creates a mechan-
ical advantage, requiring less force for pointer motion.
•
Soft dome (P/N 91P8422)
—A larger convex design with a soft texture nonsandpaper
surface.
Figure 15.13
Classic, soft rim, and soft dome TrackPoint caps.
Note
If your keyboard uses the same physical caps as the IBM/Lenovo designs, you can change
to the newer IBM/Lenovo caps as well. You can get these caps by ordering them from
