UNIT 1COMPUTER BASICS

LESSON 5INPUTOUTPUT andSTORAGE

OBJECTIVES

Identify and describe the most common output devices.

Identify and describe the most common input devices.

Identify and describe storage devices. Identify and describe how input and output

devices are connected to the computer.

INPUT AND OUTPUT DEVICES

Input devices enable a user to input data and commands to the computer to be processed.

Output devices enable the computer to give or show you the results of its processing.

Some devices can perform both input and output operations.

INPUT DEVICES- KEYBOARD

The Keyboard

- is the most widely used input device.

-As you press keys on the keyboard, an electrical signal representing that key is sent to the computer.

-Keyboards are divided into sections.

EXAMPLE OF A KEYBOARD

INPUT DEVICES- KEYBOARD

Typewriter keys: The standard alphabetic and numeric characters you would find on a typewriter.

Function keys: Special keys that perform some specific function for the application being run.

Numeric keypad: Used for mathematical operations.

Directional keys: Used to move the cursor around the screen.

INPUT DEVICES- MOUSE

The mouse is a pointing device that rolls around on a flat surface and controls the location of the pointer on the screen.

INPUT DEVICES- MOUSE

The mouse performs the following functions:

– Pointing: Placing the on-screen pointer at a specific place

– Clicking: Pressing and releasing the mouse button

INPUT DEVICES- MOUSE

– Dragging: Holding down the mouse button and dragging an object to a new location by dragging the mouse

– Double-clicking: Pressing and releasing the mouse button twice very quickly

– Right-clicking: Pressing the right mouse button

Other Pointing Devices

Other devices that control the on-screen pointer:

-Trackball: This is like a mouse turned upside down. You roll a ball around with your fingers to control the location of the pointer.

-These frequently are found on notebook computers.

EXAMPLE OF A TRACKBALL

Other Pointing Devices (cont.)

-Joystick and wheel: Joysticks consist of a metal or plastic handle mounted on a base that you can move in any direction to move the pointer or other object.

-These typically are used for video games.

-Most have buttons that can be pushed or clicked to control input/output.

EXAMPLE OF A JOYSTICK & WHEEL

Other Pointing Devices (cont.)

-Pointing stick: A pressure-sensitive device that resembles a pencil eraser; found mostly on notebook computers

-Graphics tablet: A flat drawing surface connected to the computer

-The user draws on the surface, and the figures or writing on the tablet can be input to the computer for processing

EXAMPLE OF A GRAPHICS TABLET

Other Pointing Devices (cont.)

-Touch display: Screens that contain pictures or shapes that the user can press to input that data

-Stylus/digital pen: Used with mobile devices to input data

-Touchpad: Used mostly in laptop/notebook computers

EXAMPLE OF A TOUCH DISPLAY

EXAMPLE OF A DIGITAL PEN

EXAMPLE OF A TOUCHPAD

Other Pointing Devices (cont.)

-Audio/voice input: Inputting sound and/or voice.

– These usually require a microphone and special voice recognition software to be installed on the computer.

EXAMPLE OF AN AUDIO/VOICE INPUT

Other Pointing Devices (cont.)

Scanners: Devices that can convert a graphical image into a digital image and input it to the computer – Types of scanners include

Image scanners for scanning images and textBar code scanners to read product bar codesMagnetic scanners to read the magnetic strip

on a credit card

EXAMPLE OF A SCANNER

Other Pointing Devices (cont.)

Digital cameras: Used to take pictures and store them on a magnetic disk instead of on film– Their images can be input directly into the

computer. Video input: Input from a camcorder or VCR

using video capture cards

EXAMPLE OF A DIGITAL CAMERA

Other Pointing Devices (cont.)

Biometric input: Uses

fingerprint, face,

handwriting, and

voice for identification

Magnetic Storage Devices

Floppy disks: Small, portable disks that hold a limited amount of data

Hard disks: Large-capacity and fast-access storage devices

Magnetic Storage Devices (cont.)

Zip disks: Auxiliary storage devices that can hold large quantities of data and can be portable

Magnetic tape drives: Used for making system backups andstoring large quantities of data

Optical Storage Devices

CD-DA: Audio CD CD-R: This drive allows you to read and to write to a

compact disk. CD-ROM: Can hold large amounts of data, but is read-

only access. CD-RW: Can be written on several times DVD-ROM: Read-only DVD format DVD-R: Similar to CD, but holds more data; read-only DVD-RW: Can be written on several times PhotoCD: Used for storing digital photographs on a CD

Solid-State Storage Media

Non-volatile removable media Miniature mobile media

– Uses integrated circuits USB flash drive

– Connects to the computer

via a USB port

Caring for Storage Media

To safeguard your data from damage, follow these tips when dealing with removable media:– Keep away from magnetic fields.– Avoid extreme temperatures.– Never try to disassemble the case.– Remove media from drive when not being

used.

Caring for Storage Media (cont.)

Tips for dealing with storage media (cont.)– Write-protect important data.– Hold optical disks at their edges.– Never remove the media from the drive if

the access light is on.– Keep disks in a sturdy case when

transporting them.

Output Devices—Monitors

Monitors are used to display video output to a user.

Monitors may be monochromatic or color.– Monochromatic monitors display output in

a single-color display.

EXAMPLE OF A MONITOR

LCD monitor PLASMA monitor

Output Devices—Printers

Printers are used to create a hard copy of a document or image.– Printers vary by speed, quality, and price

The most popular types of printers are– Laser: Produce images using the same

techniques as copier machines

Output Devices—Printers (cont.)

– Ink jet: Use fine nozzles to spray ink onto the page as the paper passes through

– Dot matrix: Work similarly to a typewriter in that ink is transferred to the paper by some part of the printer striking a ribbon to transfer an image

EXAMPLES OF PRINTERS

LASER INKJET DOTMATRIX

Other Types of Output Devices

Speakers and headsets

Fax machines and fax modems

Multifunctional devices

Data projectors

Connecting I/O Devices to the Computer

Input and output devices must be connected to the computer before they can be used.

Connecting I/O devices to the computer:– Plug the device into an existing socket or port on

the back of the computer.– Install an expansion card with the port you need

included on the back of the card.– Connect wirelessly.

Summary

Input devices enable you to input data and commands into the computer.

The most common input devices are the keyboard and mouse.

Other types of input devices include trackball, joystick and wheel, pointing stick, graphics tablet, touch display screen, stylus, voice recognition devices, touchpad, scanner, digital camera, video input, and biometric input.

Summary (cont.)

To maintain a permanent copy of data, you should store it on some type of storage medium.

The three categories of storage media are magnetic storage, optical storage, and solid-state storage.

Monitors and printers are examples of output devices.

Summary (cont.)

Monitors produce soft copy. Printers are used to produce a paper or

hard copy of the processed result. Criteria for selecting a printer include

speed, print quality, and cost. Input and output devices must be

physically connected to the computer.

Summary (cont.)

Some input devices communicate with the computer through a physical connection.

Wireless devices communicate with the computer through infrared or radio waves.

PHOTOS CURTESY OF YAHOO IMAGES