HARDWARE AND MULTIMEDIA

CHAPTER 4

Created by S Cox

Objectives Explain the basic differences between Macintosh

and Windows computers Describe what devices are used for entering

information into computer systems Discuss different kinds of input and output

devices for multimedia Compare different kinds of storage devices and

discuss their advantages and disadvantages Describe the computer parts that process data Learn how computers are connected locally and

around the world

Learning About Computers PCs are computers that can be:

• Used by individuals at home, work, or school• Desktop models or portable laptop models• Connected to a server in a network

One of the principal differences among computers is the operating system. • Operating systems enable computers to run software

and perform basic tasks.• Most personal computers use Windows or Macintosh

(MacOS) operating systems.• Windows and MacOS operating systems are not

compatible.

Learning About Computers Difference between desktop and laptop

computers:Desktop computers are meant to be left in

one location and laptops are portable Personal digital assistants –

computers that are small enough to hold in the palm of your handToday’s PDAs are just about as smart as a

desktop or laptop computer

Learning About Computers A server is a computer that manages

files and other resources for a networkSome are no bigger than a PC, others are

larger and more powerful

Input Devices

Input is any information you enter into a computerKeyboard – used to enter textMouse - used to select options by pointing

and clicking items on the display screenKeypads – used by touching the characters

with a stylus rather than typing

Input Devices Cursor – symbol on the screen

that points to specific information

Trackball – a popular variation on the mouse…instead of moving the mouse you move a ball that is set in a stationary holder. Advantage – puts less strain on the

arms and uses less desk surface Touchpad – a flat, built-in

pad…press and move your finger on the touchpad to move the cursor

Input Devices Sound input devices

MicrophonesDigital recordersSynthesizers (device for translating musical

notes into a digital format for computer input and processing) and musical keyboards

Digital CamerasDigital Still Cameras - picturesDigital Camcorders – record video and soundWebcams – digital video camera connected to

the Web

Input Devices Graphics tablets – also called

digitizing tablet or digitizer; used to create sketches and drawings in digital format

Scanners – used to convert any printed picture or document to a digital file to upload to a computerOptical character recognition (OCR) – software used to convert

scanned text from a paper document or a graphic file into a format that can be edited on a computer

Joysticks – used to send instructions to the computer through a directional lever and one or more control buttons typically used for games

Output and Display Devices Output – Any information that a computer

produces Monitors – display screen

Cathode ray tube (CRT) – resembles a TV; an electron beam continuously scans the back of the screen to create images by lighting up phosphor

Liquid-crystal display (LCD) – works like a calculator display; applies voltage to liquid crystals which are sandwiched between to magnetic, to light them up; represent color by varying the amount of light that shines through

Output and Display Devices

Monitors depend on a graphics card (circuit board for processing and displaying graphics)

Touch Screen – output device, a display, and an input device; ATMs and PDAs use them; used when peripherals (device that is used with a computer but not essential) are inconvenient

Output and Display Devices Plasma Displays – flat-panel; creates

images by passing electrical impulses through a neon/xenon gas mixture sandwiched between two sealed glass plates with electrodes on their surface

LEDs – screens that light up when electricity passes through them like PDAs or cell phones

Projectors

Output and Display Devices Printers

Ink-jet – spray ink at the paper through tiny nozzles

Laser – uses a laser beam and magnetism to transfer fine powder called toner to the paper; similar to a copier

LCD and LED – use magnetism and toner, but instead of beams they use liquid crystals and light-emitting diodes

Speakers – computer needs audio card

Digital Storage Devices

Hard drives – built in for storing software and informationStores information magneticallyHas an arm with a sensor on the end that

reads and writes data as it spins

Digital Storage Devices

Removable storageCDs – disc used to store and read digital materialCD-ROM – can only read data but cannot write to

the discDVDs – optical disksFloppy disks – flexible magnetic disk…becoming

obsoleteZip disks – developed by Iomega CorporationMemory cards – small removable digital input

modules; used by cameras and audio recordersUSB memory drives – also called travel drives, jump

drives, memory sticks, or thumb drives

Processing Components

Processing includes all the calculations and other operating a computer performs on your input to turn it into output.

Processing takes place on microprocessors, or chips (usually smaller than a fingernail, contains millions of electronic components)

Processing Components

Central Processing Unit – controls the computer’s logic and its ability to carry out instructions; used by almost all digital devices (alarm clocks, digital cameras, and CD players)Vary in processing speed; measured in megahertz

(MHz) or gigahertz (GHz)…the faster the speed the faster your programs will run

Part of the motherboard (main circuit board) Memory

Random Access Memory (RAM) – where the computer stores data while you are working on it○ Measured in bytes

Elements of Communication In order to exchange files and share

resources, computers:Require special input and output devicesMust be part of a network, such as:

○ The Internet○ Local area network (LAN) – connect

computers in one location○ Wide area network (WAN)– connects

computers across a wide geographical area

Elements of Communication

Types of connectionsDial-up connection – a computer uses a modem and a

standard telephone line…obsoleteBroadband connection – uses dedicated telephone

lines or cable television equipment …constant connection○ Some use DSL (digital subscriber lines) – high capacity

telephone lines; the computer must be within a few miles of a telephone company

transmitter

○ No DSL – can use cable television or satellite television companies

Elements of Communication Devices for Communications

Modems and Broadband Connections – cable modem

Modems and Wireless Connections – some modems are wireless and use cellular telephone technology

Network cards – to connect to a network a PC needs a network interface card (NIC)

Routers – used to connect two or more LANs