Chapter 6 Input and Output

Scanning Devices

Convert scanned text and images into a form that the system unit can process. There are five types of scanning devices: Optical scanner, also known simply as a scanner, accepts documents consisting of text and/or images and converts them to machine-readable form.

Printers

Translates information that has been processed by the system unit and presents the information on paper. Printer output is often called hard copy.

Combination Input-Output devices

Headsets Telephones

Pointing Devices

Mouse Touch Screen Controller Stylus

Digital cameras

images are captured digitally on a memory card or in the camera's memory and it can be viewed immediately and even placed on a web page within minutes

What is Input?

o Any data or instructions that are used by a computer. o Can come directly from end user or from other sources. o Input devices are hardware used to translate words, numbers, sounds, images, gestures, and actions that people understand into a form that the system unit can process. o In addition to keyboards and mice, there are a wide variety of other input devices including pointing, scanning, image capturing, and audio-input devices.

Card Readers

o Credit cards, access cards, id cards, debit cards typically have the user's name, some type of identification number, and signature on the card. o Encoded information is often stored on the card and card readers interpret this encoded information. o Magnetic card reader - is the most common; encoded information is stored on a thin magnetic strip located on the back of the card. When the card is swiped through the magnetic card reader, the information is read. o Smart cards - include additional security in the form of a microchip embedded in the credit card

Bar Code Readers

o Handheld wand readers or platform scanners. o Contain photoelectric cells that scan bar codes, the vertical zebra-striped marks, printed on product containers. o UPCs (Universal Product Codes) are widely used by retial stores to automate the processes to check out customers, or change product prices, and to maintain inventory records o MaxiCode is widely used by the United Parcel Service (UPS) and others to automate the process of routing packages, tracking in transit packages, and locating lost packages. o Smartphones with apps can also scan codes. See Figure 6- 10.

Monitors

o Most frequently used output device. Also known as display screen o Present visual images of text and graphics. o Output is often referred to as soft copy. o Monitors vary in size, shape, and cost.

Keyboard Entry

o One of the most common ways to input data is by keyboard. o Keyboards convert numbers, letters, and special characters that people understand into electrical signals. o Electrical signals from the keyboard are sent to, and processed by, the system unit. o Most keyboards use an arrangement of keys given the name QWERTY.

What is Output?

o Output is processed data or information, and typically takes the form of text, graphics, photos, audio, and/or video. o Output devices are any hardware used to provide or to create output. o They translate information that has been processed by the system unit into a form that humans can understand. o Most widely used output devices are monitors, printers, and audio-output devices.

Ergonomics

the study of human factors related to things people use. It is concerned with fitting the task to the user rather than forcing the user to contort to do the task. For computer users and manufactures this means devising ways that input and output devices can be used and designed to increase ease of use and to avoid health risks. Sitting in front of a screen in awkward positions for long periods may lead to physical problems such as eyestrain, headaches, and back pain. Computer users can alleviate these problems by taking frequent rest breaks and by using well-designed computer furniture

Radio-frequency identification tags

tiny chips that can be embedded in most everything. See Figure 6-11. They contain electronically stored information. They are used to track and locate lost pets; to monitor production and update inventory; and to record prices, product descriptions, and locations of retail items.

Audio-Output Devices

translate audio information from the computer into sounds that people can understand. Speakers Headphones Bluetooth

Voice recognition systems

use a microphone, a sound card, and special software. These systems allow users to operate computers and to create documents using voice commands.