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.