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 hand

Today’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 network

Some are no bigger than a PC, others are

larger and more powerful

Input Devices

Input is any information you enter into a

computer

Keyboard – used to enter text

Mouse - used to select options by pointing

and clicking items on the display screen

Keypads – 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 Microphones

Digital recorders

Synthesizers (device for translating musical notes into a digital format for computer input and processing) and musical keyboards

Digital Cameras Digital Still Cameras - pictures

Digital Camcorders – record video and sound

Webcams – 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 computer

Optical 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 information

Stores information magnetically

Has an arm with a sensor on the end that

reads and writes data as it spins

Digital Storage Devices

Removable storage

CDs – disc used to store and read digital material

CD-ROM – can only read data but cannot write to the disc

DVDs – optical disks

Floppy disks – flexible magnetic disk…becoming obsolete

Zip disks – developed by Iomega Corporation

Memory cards – small removable digital input modules; used by cameras and audio recorders

USB 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 devices

Must 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 connections

Dial-up connection – a computer uses a modem and a

standard telephone line…obsolete

Broadband 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