Hardware Reference
In-Depth Information
Many credit the Macintosh with inventing the mouse and GUI, but as you can see, this technology was
actually borrowed from others, including SRI and Xerox. Certainly Microsoft Windows has
popularized this interface and brought it to the legion of Intel-based PC systems.
Although the mouse did not catch on quickly in the PC marketplace, today the GUIs for PC systems,
such as Windows, practically demand the use of a mouse. Therefore, virtually every new system sold
at retail comes with a mouse. And, because the mice packaged with retail systems are seldom high-
quality or up-to-date designs, sooner or later most users are in the market for a better mouse or
compatible pointing device.
Mice come in many shapes and sizes from many manufacturers. Some have taken the standard mouse
design and turned it upside down, creating the trackball. In the trackball devices, you move the ball
with your hand directly rather than moving the unit itself. Trackballs were originally found on arcade
video games, such as
Missile Command
, and are popular with users who have limited desk space. In
most cases, the dedicated trackballs have a much larger ball than would be found on a standard
mouse. Other than the orientation and perhaps the size of the ball, a trackball is identical to a mouse
in design, basic function, and electrical interface. Like many recent mice, trackballs often come in
ergonomic designs, and the more recent models even use the same optical tracking mechanisms used
by the latest Microsoft and Logitech mice.
The largest manufacturers of mice are Microsoft and Logitech; these two companies provide designs
that inspire the rest of the industry and each other and are popular OEM choices as well as retail
brands. Although mice can come in different varieties, their actual use and care differ very little. The
standard mouse consists of several components:
• A housing that you hold in your hand and move around on your desktop.
• A method of transmitting movement to the system: either ball/roller or optical sensors.
• Buttons (two or more) or touch sensors for making selections.
• A wheel or touch sensors for vertical and even horizontal scrolling. Some wheels tilt for
horizontal scrolling or can be pressed to act as a button.
• An interface for connecting the mouse to the system. Conventional mice use a wire and
connector, whereas wireless mice use a radio frequency (RF) or infrared (IR) transceiver in
both the mouse and a separate unit connected to the computer to interface the mouse to the
computer.
The housing, which is normally made of plastic, consists of few moving parts. On top of the housing,
where your fingers normally rest, are buttons. There might be any number of buttons, but mice
designed for PCs have always had two buttons, and since 1996 they have a scroll wheel or other
device as well. Although the latest versions of Windows support scrolling mice, other features
supported by the vendor, including additional buttons, still require installing the vendor's own mouse
driver software.
Mouse Sensitivity
Mouse sensitivity is measured in DPI (dots per inch), which is also sometimes called PPI (pixels per
inch). A standard mouse is calibrated to return position data at 400 DPI, while high-definition mice
are calibrated to return data at 800 DPI or higher. There are some gaming mice that can be configured
to rates of 5,000 DPI or more.
The higher the DPI setting, the faster and farther the pointer will move in relation to a given amount of
