8. INPUT, OUTPUT AND STORAGE DEVICES I/O UNITS

INPUT DEVICE A piece of hardware that is used to

enter data into a computer. Examples of an input devices:

- Keyboard - Scanner- Mouse - Microphone- Touchpad - Digital camera- Joystick - Barcode reader

KEYBOARD The most common and widely used

input device. Made up of buttons called ‘keys’. The

keys are arranged into sections:alphabet keys, Function keys (F1,F2), Numeric keys, command keys (insert, delete, home)

Most commonly called ‘QWERTY’ keyboard.

MOUSE Invented by Douglas Engelbart in 1963. Allows an individual to control a pointer in a

graphical user interface (GUI). A central wheel allows you to scroll up and

down the page. Left clicking usually lets you put

your cursor at a certain point. Right clicking usually display a list of menu items from which to choose.

TOUCHPAD An input device which is usually found

on a laptop computer.

JOYSTICK An input device that looks similar to a

control device you would find on an arcade game at your local arcades.

Allows an individual to easily move an object in a game such as navigating a plane in a flight simulator.

SCANNER Input device that allows a user to take

an image and/or text and convert it into a digital file, allowing the computer to read and/or display the scanned object.

Commonly connected to a computer USB and parallel ports.

MICROPHONE Sometimes abbreviated as mic, a

microphone is a hardware peripheral originally invented by Emile Berliner in 1877.

Allows computer user to input audio into their computers.

DIGITAL CAMERA A type of computer that stores the

pictures or video it takes in electronic format instead of to film.

The quality of the image is dependent on the resolution or the number of pixels.The more pixels, the better the quality and clarity of the image.

Most digital cameras range from 4 – 12 Megapixels.

BARCODE READER An electronic device for reading printed

barcodes. It consists of a scanner, a decoder

(either built-in or external) , and a cable used to connect the reader with a computer.

OUTPUT DEVICE Output devices are things we use to get

information OUT of a computer. Examples of an output devices:

- Monitor- Printer- Speaker- Plotter

MONITOR The monitor displays the computer’s

user interface and open programs, allowing user to interact with the computer, typically using the keyboard and mouse.

Most modern monitors are built using LCD technology and are commonly referred as flat screen displays.

PRINTER A device that prints text or illustrations

on paper. Different types of printers: - Dot-Matrix printer

- Laser printer- Ink-Jet printer

SPEAKER Speakers take electronic signal and

then convert them into sound.

PLOTTER Special type of printer which is able to

draw high quality images on very large pieces of paper.

Used by engineers, architects and map-makers to draw plans of buildings, diagrams of machines or large scale maps.

STORAGE DEVICE A hardware device designed to store

information. Two types:

- Primary storage e.g. RAM- Secondary storage e.g. diskette, hard disk,

pendrive etc.