CompTIA A+® Certification All-In-One For Dummies®, 2nd Edition

2.2. Catching the Mouse

The other popular input device found on computer systems today is the mouse. The mouse is one of the primary input devices because of the graphical user interface (GUI) features of today's operating systems. The following sections identify the different types of mice and how to install them.

2.2.1. Types of mice

You can find three types of mice on today's desktop computer systems: mechanical mice, opto-mechanical mice, and optical mice.

• Mechanical: A mechanical mouse was the only type of mouse used with computers for many years. The mechanical mouse uses a rubber ball that moves a pair of wheels inside the mouse. The internal wheels capture the horizontal and vertical movements of the mouse and then send that information to the computer. The movement is then displayed onscreen.

• Opto-mechanical: The opto-mechanical mouse is a very popular mouse today. It uses a rubber ball that moves rollers that control the movement of a disc — the encoding disc — which has holes along the side of it.

  The prefix "opto" comes into play because LEDs and sensors use an infrared light beam to determine the movement of the mouse. See Figure 2-7. When the rubber ball moves the encoding disc, the infrared beam passes through the holes on the encoding disc, indicating that the mouse has moved and in which direction.

  Figure 2.7. As the mouse moves, the holes and solid areas of the encoding disc help determine movement.

• Optical: An optical mouse differs from an opto-mechanical mouse ...