Jason Mitchell
NT1110 Computer Structure & Logic
Mod 2 Short Answer
4-10-15

I/O Devices I/O devices enable us to control the computer and display information in a variety of ways. In computing, input/output or I/O is the communication between a computer and the outside world, possibly a human or information processing systems. Inputs are the signals or data received by the system and outputs are the signals or data sent from it.
The computer keyboard is used to enter text information into the computer, as when you type the contents of a report. The keyboard can also be used to type commands directing the computer to perform certain actions. Typical pointing devices are: mouse, trackball, touch pad, track-point, graphics tablet, joystick, and touch screen. Your computer must produce a video signal that a monitor can display. This may be handled by circuitry on the motherboard, but is usually handled by a video card in one of the computer’s expansion slots; often the slot is a special one dedicated to video use, such as an AGP slot (Accelerated Graphics Port).
Video cards are also called video display adapters, and graphics cards. Many video cards contain separate processors and dedicated video memory for generating complex graphics quickly without burdening the CPU. These accelerated graphics cards are loved by gamers.
A flat panel display usually uses an LCD (Liquid Crystal Display) screen to display output from the computer. The LCD consists of several thin layers that polarize the light passing through them. The polarization of one layer, containing long thin molecules called liquid crystals, can be controlled electronically at each pixel, blocking varying amounts of the light to make a pixel lighter or darker. Other types of flat panel technology exists, (such as plasma displays) but LCDs are most commonly used in computers, especially laptops. A modem is a device or program that enables a computer to transmit or receive data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts between these two forms. Output, data/information leaves the computer via it. If it is a combination printer/fax/scanner it could be both. When printing it is an output device, when scanning it is an input device.