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.

PC Connections

A typical computer connects to the world around it in three different ways:

Input/output devicesPortsNetworking.

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:

DisplayKeyboardMouseRemovable 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 AreaTwo 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.

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.

Internet/Network

Modem - This is the standard method of connecting to the Internet.Local area network (LAN) card - This is used by many computers, particularly those in an Ethernet office network, to connected to each other. Cable modem - This type of modem uses the cable TV system in your home to connect to the Internet.

Digital Subscriber Line (DSL) modem - This is a high-speed connection that works over a standard telephone line. Very high bit-rate DSL (VDSL) modem - A newer variation of DSL, VDSL requires that your phone line have fiber-optic cables.

Other Peripherals

Gaming devices: gamepads, sidewinder, headsetsWebcamsGraphic tabletsMidi devices: keyboards and other instrumentsMany other devices exist that are used in special/specific situations such as special probes for science, voice recognition hardware, simulator devices, etc…