Hardware Reference
In-Depth Information
both vendors means you can have the latest optical technology for about the price of a
good ball-type mouse.
Figure 15.10
shows the interior of a typical optical mouse.
Figure 15.10
The LED inside an optical mouse illuminates the surface by blinking many times per second.
The light is reflected from the mousing surface back to the sensor, which converts the information into di-
gital form and sends it to the computer.
All optical mice have a resolution of at least 400 dpi. However, for better performance,
some optical mice have adjustable sensors that offer up to 2,000 dpi resolution or even
higher. These are often sold as gaming mice because the higher resolution offers faster
response for quick game movements. Many mice now incorporate IR laser technology
sensors, which increase the resolution of the sensor, allowing for improved tracking on
glossy or transparent surfaces.
Optical mice are available as corded or wireless models, which use either IR or RF trans-
ceivers to replace the cable. A receiver is plugged into the USB or mouse port, and the
battery-powered mouse contains a compatible transmitter. Wireless ball-type mice are
usually much larger than ordinary mice because of the need to find room for both the
bulky ball mechanism and batteries, but wireless optical mice are about the same size as
high-end corded mice.
Tip
Corded mice have cables that are typically 4 to 6 feet in length. If you have a choice on the
lengthofcabletobuy,getalongerone.Thisallowseasierplacementofthemouseinrelation
to your computer. Extension cables can be used if necessary to extend the distance.
Afterthemouseisconnectedtoyourcomputer,itcommunicateswithyoursystemthrough
the use of a device driver, which can be loaded explicitly or built into the OS software.
For example, no separate drivers are necessary to use a mouse with modern OSs such as
Windows, but using the mouse with older OSs such as DOS requires a separate driver to
be loaded from the CONFIG.SYS or AUTOEXEC.BAT file. Regardless of whether it is
