LEARNING OBJECTIVES

• To learn the common input devices and their basic characteristics.

How do we communicate to the computer ?

AND

• To learn the common output devices and their basic characteristics. 

How the computer communicate to us?

INPUT DEVICES

• Entering data or instructions into a computer is called an input. Therefore an input device is device which enters a data or instructions into a computer.

• Input devices are necessary to convert data into a form which can be understood by computers.

SOME EXAMPLES OF INPUT DEVICES are:

MOUSE

• This input device controls the cursor on the computer screen. It has two or three buttons and a cable connecting it to the computer. It is quite easy to operate a mouse, the user simply moves the cursor along the table. Once the cursor is at the desired location, the user can give instructions to the computer by clicking the button.

• A keyboard is the set of typewriter-like keys that enables you to enter data into a computer. Computer keyboards are similar to electric-typewriter keyboards but contain additional keys. The keys on computer keyboards are often classified as follows:

• alphanumeric keys -- letters and numberspunctuation keys -- comma, period, semicolon, and so on.special keys -- function keys, control keys, arrow keys, Caps Lock key, and so on.

KEYBOARD

JOYSTICK• A lever that moves in all directions and

controls the movement of a pointer or some other display symbol. A joystick is similar to a mouse, except that with a mouse the cursor stops moving as soon as you stop moving the mouse. With a joystick, the pointer continues moving in the direction the joystick is pointing. To stop the pointer, you must return the joystick to its upright position. Most joysticks include two buttons called triggers.

• Joysticks are used mostly for computer games, but they are also used occasionally for CAD/CAM systems and other applications.

This looks like a photocopying machine, its function is to scan any document placed on its flat glass and send the contents to the computer.

• There are 2 types of scanners:  1. Flatbed scanners2. Hand held scanners

SCANNER

• The devices which are used to display the data to the user either in the form of hard copy or soft copy are called output devices.

OUTPUT DEVICES

What is it? • The information we obtain from the

computer is called an output .• The computer presenting this

information is called the output device.• It is the display screen of a computer

There are several output devices:• Monitor• Printer • Plotter• Speaker

MONITOR

• The monitor is one of the most important output devices, it is used to display text and pictures.

•   It is the display screen of a computer Images on a monitor are made up of thousands of tiny coloured dots called PIXELS.

• The monitor is also known as Visual Display Unit (VDU) The screen is the surface of monitor which display the text and pictures.

PRINTERS•  They are use to create a hard copy of your work.• Most printer produce work on paper.• These are in different types.• Impact - Have mechanical contact in between paper

& printing head.• Non Impact - No mechanical contact between paper

& printing head.• There are 4 type of printer : Laser printers Ink-jet printers Dot-matrix printers Plotters

SPEAKERS

• Output sound that is produced or is stored by the computer.

• They are required to play sound files attached to presentations or websites.

• It is a very important part of a home entertainment system. 

HEADPHONES• Headphones give sound output from

the computer.• They are similar to speakers, except

they are worn on the ears so only one person can hear the output at a time.

PREPARED BY:GEETUIX- B