Hardware Reference
In-Depth Information
All these devices are treated asmice bythe OSbutofferradically different options forthe
user in terms of comfort. If you're not satisfied with a regular mouse and don't want to
use an integrated pointing stick such as the TrackPoint II/III/IV, look into these options.
Touch Pads
The first touch pad was included on the ill-fated Gavilan portable computer in 1982;
however,itdidn'tcatchonuntilmanyyearslater.Cirqueoriginatedthemoderntouchpad
(also called a
track pad
) pointing device in 1994. Cirque refers to its technology as the
GlidePoint and has licensed the technology to other vendors such as Alps Electric, which
alsousesthetermGlidePointforitstouchpads.TheGlidePointusesaflat,squarepadthat
senses finger position through body capacitance. This is similar to the capacitance-sensit-
ive elevator button controls you sometimes encounter in office buildings or hotels.
When it is used on a portable computer's keyboard, the touch pad is mounted below the
spacebar,anditdetects pressureapplied byyourthumbsorfingers.Transducersunderthe
pad convert finger movement into pointer movement. Several laptop manufacturers have
licensed this technology from Cirque and have incorporated it into their portable systems.
Touch pads are also integrated into a number of mid-range to high-end keyboards from
many vendors. When used on a desktop keyboard, touch pads are often offset to the right
side of the keyboard's typing area.
Touch pads feature mouse buttons, although the user also can tap or double-tap on the
touch pad's surface to activate an onscreen button located under the touch pad's cursor.
Dragging and dropping is accomplished without touching the touch pad's buttons; just
movethecursortotheobjecttobedragged,pressdownonthepad,holdwhilemovingthe
cursor to the drop point, and raise the finger to drop the object. Some recent models also
feature additional hot buttons with functions similar to those on hot-button keyboards, as
well as a vertical scrollbar on the side and the capability to tap the touch pad to simulate a
mouse click.
The primary use for touch pads has been for laptop computer- and desktop key-
board-integrated pointing devices, although Cirque and Alps have both sold standalone
versions of the touch pad for use as a mouse alternative on desktop systems. Cirque's
touchpadscanbepurchaseddirectfromtheCirquewebsite.TheSmartCatProTouchpad
has enhanced software to support touch gestures, has programmable hot buttons, and in-
cludes other features to make web surfing easier.
Althoughithasgainedwideacceptance,especiallyonportablecomputers,touchpadtech-
nology can have many drawbacks for some users. Operation of the device can be erratic,
depending on skin resistance and moisture content. The biggest drawback is that to op-
erate the touch pad, users must remove their hands from the home row on the keyboard,
