Peripherals

Definition

Peripherals are pieces of hardware that you add

to your computer.

All components that do not make up the

motherboard are considered peripheral devices.

To keep things simple, we will consider any

component outside of the main box a peripheral

device.

Input/Output

No matter how powerful the components inside

your computer are, you need a way to interact

with them. This interaction is called

input/output (I/O).

The most common types of I/O in PCs are:

Display

Keyboard

Mouse

Removable storage

Display

The display is the primary device for displaying

information from the computer.

Often referred to as a monitor when packaged

in a separate case, the display is the most-used

output device on a computer. The display

provides instant feedback by showing you text

and graphic images as you work or play.

Important Features

liquid crystal display (LCD) vs. cathode ray tube

(CRT)

Resolution refers to the number of individual

dots of color, known as pixels, contained on a

display.

identified by the number of pixels on the horizontal

axis (rows) and the number on the vertical axis

(columns), such as 800x600.

Aspect Ratio and Viewable Area

Two measures describe the size of your display: the aspect ratio and the screen size. Historically, computer displays, like most televisions, have had an aspect ratio of 4:3. This means that the ratio of the width of the display screen to the height is 4 to 3. For widescreen LCD monitors, the aspect ratio is 16:9 (or sometimes 16:10 or 15:9).

For LCD’s, the aspect ratio is equal to the screen size.

Touch Screen

A touchscreen is an electronic visual display that

the user can control through simple or multi-

touch gestures by touching the screen with a

special stylus/pen and-or one or more fingers.

Some touchscreens use an ordinary or specially

coated gloves to work while others use a special

stylus/pen only. The user can use the

touchscreen to react to what is displayed and to

control how it is displayed

Keyboard

The keyboard is the primary device for entering information into the computer.

When you look at all the extras and options that are available for new computer keyboards, it can be hard to believe that their original design came from mechanical typewriters that didn't even use electricity.

Now, you can buy ergonomic keyboards that bear little resemblance to flat, rectangular models with ordinary square keys. Some flashier models light up, roll up or fold up, and others offer options for programming your own commands and shortcuts.

Pointing Device (mouse)

The mouse is the primary device for navigating and interacting with the computer.

Mice first broke onto the public stage with the introduction of the Apple Macintosh in 1984, and since then they have helped to completely redefine the way we use computers.

Every day of your computing life, you reach out for your mouse whenever you want to move your cursor or activate something. Your mouse senses your motion and your clicks and sends them to the computer so it can respond appropriately.

Removable storage

Removable storage devices allow you to add

new information to your computer very easily,

as well as save information that you want to

carry to a different location.

Four main types:

Floppy disk: The most common form of removable

storage, floppy disks are extremely inexpensive and

easy to save information to.

CD-ROM (compact disc, read-only memory): is a popular form of distribution of commercial software. Many systems now offer CD-R (recordable) and CD-RW (rewritable), which can also record.

DVD-ROM (digital versatile disc, read-only memory): is similar to CD-ROM but is capable of holding much more information. (nearly 7 times more). Also available with –R and –RW capabilities. These drives allow to read and write to both DVD and CD formats.

Flash memory: Based on a type of ROM called

electrically erasable programmable read-

only memory (EEPROM), Flash memory

provides fast, permanent storage. CompactFlash,

SmartMedia and PCMCIA cards are all types of

Flash memory.

Ports

Parallel - This port is commonly used to

connect a printer or scanner.

Serial - This port is typically used to connect an

external modem.

Universal Serial Bus (USB) - Quickly

becoming the most popular external connection,

USB ports offer power and versatility and are

incredibly easy to use.

FireWire (IEEE 1394) - FireWire is a very

popular method of connecting digital-video

devices, such as camcorders or digital cameras,

to your computer.

Other Peripherals Printers

Scanners

Speakers

Gaming devices: gamepads, sidewinder, headsets

Webcams

Graphic tablets

Midi devices: keyboards and other instruments