ITBIS105 1

Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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• Avoid hackers and viruses • Protect your privacy• Understand the real privacy and security

risks• Use the Internet wisely• Avoid online annoyances• Maintain your computer• Make good purchase decisions • Integrate the latest technology

Being a Savvy Computer User and Consumer

Digital Home

• In a digital home, you can control home systems from your computer and via the Internet.


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Digital Home - Components

• Media computer with:– TV tuner– Radio tuner– Media software– Blu-ray, DVD, and/or CD– Network adapter

– A network– A digital television– A digital media

adapter– A universal remote


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• The on/off state of a switch represents one bit of data.

• Bit (binary digit)– On = 1– Off = 0

OFF

0

Switches Representing Data

ON

1

01

OR = 1 bit


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Bits and Bytes: The Language of Computers

• Bit– Binary digit– 0 or 1

• Byte– 8 bits

• Each letter, number, and character = a string of eight 0s and 1s

0000 1111Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

Representing Letters and Symbols

• American Standard Code for Information Interchange (ASCII)– 8 bits = 1 byte = alphanumeric character or

symbol– 256 different combinations

• Unicode– 16 bits equal 1 byte– 96,000 different combinations; used for all

languagesCopyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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How Much Is a Byte?


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Mice• Optical mouse

– Needs no mouse pad– Doesn’t need cleaning– Is more expensive

• Trackball– Easier on wrists– Stays stationary on desk

• Wireless – Uses radio or light waves


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New Mouse Features• Instant viewer• Magnifier• Customizable

buttons• Web search


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Monitor Types• CRT (Cathode-Ray

Tube)– Less expensive– Uses much more space– Uses more energy– Offers better viewing angles– Legacy technology

• LCD (Liquid Crystal Display)– More expensive– Uses far less space– More energy efficient– Less viewable from an angle


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The Front Panel• Power control• Drive bays• Memory card

reader• Productivity ports


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Power Controls

• Power-on button: Turns on system, should not be used to turn it off

• Other options: – Sleep mode– Hibernation– Warm boot


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Inputting Sound• Microphones are

used for:– Podcasts– Video-

conferencing– Internet phone

calls– Speech

recognition


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Other Input Devices• EPOS Digital Pen• Webcam

– Live video


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Input Devices for the Physically Challenged

• Visual impairments– Voice recognition– Keyboards with large keys– On-screen keyboards

• Motor control issues– Special trackballs– Head-mounted devices


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Storage Media Capabilities


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On the Back

• Ports for peripherals• Types of ports:

– Serial and parallel– Audio and video– USB– FireWire– Connectivity

• Ethernet• Modem


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Inside the System Unit

• Essential electronic components used to process data

• Types of components:– Power supply– Hard disk drive– Motherboard– CPU– Expansion cards


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The Motherboard

• CPU• RAM• Expansion

cards and slots

• Built-in components


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Memory Module

• Random access memory (RAM)• Stores instructions and data• Temporary (volatile) storage• Operates in nanoseconds


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Setting It All Up: Ergonomics

• Ergonomics: minimizing injury or discomfort while using the computer

• Steps to follow:– Position monitor correctly.– Use adjustable chair.– Assume proper position while typing.– Take breaks.– Ensure adequate lighting.


Ergonomics and Mobile DevicesMobile devices present ergonomic challengesErgonomic “Disease” Cause

Blackberry thumb Thumb typing without breaks or stretching can cause DeQuervains’ tendinitis in the thumbs.

iPod deafness Listening through ear buds for prolonged periods at a volume of 80 decibels or more can cause deafness.

Cellular blindness Extended viewing on tiny screens can cause eye strain and/or dry eyes.

Laptop thighs Resting a laptop directly on your lap for extended periods of time can result in 1st and 2nd degree burns.

Laptop shoulder Large, heavy, one-strap laptop bags can result in neck, shoulder, and back pain and/or strain.


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Internet Communications

• Instant messaging• Podcasts• Blogs and vlogs• Webcasts• Wikis • Voice over Internet (VoIP) • E-mail

Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 24

Social Networks

• Social networks: online personal networks– MySpace.com and Facebook.com

• Members share common interests.• Members communicate by voice, chat, IM,

video, and blogs. • Members create personalized profiles. • Growth has been explosive. • Risks must be recognized and reduced.Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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http://www.myspace.com/

http://www.facebook.com/

Group Communication

• Internet social networks • Multiplayer online game services• Chat rooms• Newsgroups• Listservs

Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall 26

URLs

• URL:– Uniform Resource Locator– Unique Web site address

URL


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Application Software


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Buying Software• Software may be purchased

– Through retail stores– Online– At computer shows– Through catalogs

• Preinstalled software • Web-based application software

– Hosted on a Web site – Requires no installation on your computer

• Discounted softwareCopyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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Freeware and Shareware

• Freeware: Copyrighted software you can get free• Beta versions: Programs still under development • Shareware: Software that allows users to run it for a

limited time free of charge• Open source:

free to use


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Wired Ethernet Networks

• Ethernet network adapters are used to connect nodes– NIC card– PC card– USB adapter

• Computers are connected to each other using unshielded twisted pair cable

Ethernet

Phone


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How Computers Are Attacked• Trojan horse• Backdoor program

– Zombies• Denial of service

attacks (DoS)• Distributed denial

of service attacks (DDoS)


The CPU Machine Cycle• Fetch

– The program’s binary code is “fetched” from its temporary location in RAM and moved to the CPU.

• Decode– The program’s binary code is decoded into commands that

the CPU understands.• Execute

– The ALU performs the calculations.• Store

– The results are stored in the registers.

“Inside the Chip” by Intel

Video Clip


Making Computers Faster• Pipelining: The CPU processes more than one

instruction at a time

Fetch Decode Execute

Store


Store

Instruction 1

Instruction 2

Nonpipelined CPU


Store


Store


Store


Store

Instruction 1

Instruction 2

Instruction 3

Instruction 4

Pipelined CPU


Cache Memory• Small amount of memory

located on or near the CPU chip

• Stores recent or frequently used instructions and data

• Used for quick access by the CPU

• Different levels of cache


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Client/Server Networks

• Server-based network– Clients and servers

• Data flows efficiently • Servers respond to

requests from clients• Servers perform specific

tasks• Scalable• Centralized


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Classifications of Client/Server Networks

• LAN– Local area

network– Computers

linked over a small geographic region


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• WAN– Wide area

network– Computers linked

over large geographic locations

• MAN– Metropolitan area

network– Computers linked

within a city or county


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• PAN– Personal area network– Wireless devices connected in close proximity to

each other• Intranet

– Private corporate network– Protected by a firewall



• Extranets– Only certain corporations or individuals can access– Useful for enabling electronic data interchange– Use virtual private networks for security

40Copyright © 2010 Pearson Education, Inc. Publishing as Prentice Hall

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Avoiding Data Collisions on an Ethernet Network


ITBIS105 1

Education

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