Kompilasi materi pti~darul

Dosen: DarulQuthni
NIDN: 0128057803
Email: darulquthni@piksiinputserang.ac.id

Introduction to Information
Technology

Session 1
Chapter 1
1.Introduction to Information Technology
1.1 Infotech Becomes Commonplace:
Cellphones, E-Mail, the Internet, & the E-World
1.2 The “All-Purpose Machine”: The Varieties of Computers
All Computers, Great & Small: The Categories of Machines
1.3 Understanding Your Computer: What If You Custom-Ordered Your Own PC?How Computers Work
1.4 Where Is Information Technology Headed?

Chapter 2
2.1 Choosing Your Internet Access Device & Physical Connection: The Quest for Broadband
2.2 Choosing Your Internet Service Provider (ISP)
2.3 How Does the Internet Work?
2.4 Email Software & Carriers
2.5 The World Wide Web
2.6 The Online Gold Mine: More Internet Resources

Using Information Technology
Chapter 1
Introduction to Information Technology

1.1 Infotech Becomes Commonplace:
Cellphones, E-Mail, the Internet, & the E-
World
•Information technology (“infotech”):

•Computers - programmable multiuse machines that convert data into
information

•Communications - electromagnetic devices and systems for communicating
over long distances

The Telephone Grows Up

• Approximately 1 billion people
using cellphones

• Internet phones are cell phones
plus:

• Email
• Web services
• Video

“You’ve Got Mail!” E-Mail’s Mass Impact

• E-mail (“electronic mail”) -
• messages transmitted over a
network
• Network - communications
system connecting two or more
computers

The Internet, the World Wide Web, & the “Plumbing of
Cyberspace”

• Cyberspace encompasses the whole wired and wireless world of
communications:

• The Internet - the “mother of all networks”

• The World Wide Web - multimedia part of Net

The E-World & Welcome to It

• E-business
• E-commerce
• E-government
• E-learning
• E-pinions
• E-tailing
• E-waste

1.2 The “All-Purpose Machine”: The
Varieties of Computers
1. Supercomputers
2. Mainframes
3. Workstations
4. Microcomputers
5. Microcontrollers

NEC Earth Simulator –
the world’s fastest computer


l Supercomputers
1. Mainframes
2. Workstations
3. Microcomputers
4. Microcontrollers

IBM z900


1. Supercomputers
2. Mainframes
3. Workstations
4. Microcomputers
5. Microcontrollers

Workstation – Sun Ultra450


1. Supercomputers
2. Mainframes HP Compaq Business Compaq Evo desktop
3. Workstations d220 tower microcomputer microcomputer

4. Microcomputers
5. Microcontrollers

Personal Digital
Laptop computer Assistant


1. Supercomputers
2. Mainframes
3. Workstations
4. Microcomputers
5. Microcontrollers

Servers

•Server - a central computer that holds collections
of data & programs for clients

•Clients - PCs, workstations, & other devices SERVER

•Server + Clients linked together form a
client/server network CLIENT

1.3 Understanding Your Computer: What If You
Custom-Ordered Your Own PC?
How Computers Work - Concept #1
The purpose of a computer is to process data into information.

• Data • Information

The raw facts and figures that are Data that has been summarized or
otherwise manipulated for use in
processed into information decision making

Computers consist of hardware and software.

• Hardware • Software

All the machinery and equipment All the instructions that tell the
in a computer system computer how to perform a task

All computers follow the same five basic operations.
1. Input

2. Processing

3. Storage Keyboard

4. Output

5. Communications Mouse

All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Case or system cabinet Processor chip

Motherboard

1. Input • Primary storage (memory) - RAM

2. Processing • Computer circuitry that
temporarily holds data waiting to
3. Storage be processed
4. Output
• Secondary storage (storage) -
ROM
5. Communications
•
• The area in the computer where
data or information is held
permanently


1. Input

2. Processing

3. Storage

4. Output

5. Communications

CD Drive

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Monitor Speakers

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Printer

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Put all the hardware together and…

You still need the software!
• System software

• Helps the computer perform
essential operating tasks and
enables the application software to
run
• and…

Application software
Enables you to perform specific
tasks--solve problems, perform
work, or entertain yourself

1.4 Where Is Information Technology
Headed?

Three Directions of Computer Development
• Miniaturization

• Speed

• Affordability

Then (1946) Now

Three Directions of Communications Development

• Connectivity

• Interactivity

• Multimedia

Interactivity

When Computers & Communications Combine:
Convergence, Portability, & Personalization

• Convergence

• Portability

• Personalization


Chapter 2
The Internet & the World Wide Web
Exploring Cyberspace

2.1 Choosing Your Internet Access Device & Physical
Connection: The Quest for Broadband

• Bandwidth - an expression of how much data
can be sent through a communications channel
in a given amount of time

• Baseband – Allows only one signal at a time

• Broadband – Several signals can be sent at once

Choosing Your Internet Access Device & Physical
Connection: The Quest for Broadband

• Download - to transmit
data from a remote
computer to a local
computer

• Upload - to transmit
data from a local
computer to a remote
computer

Telephone (Dial-Up) Modem: Low Speed but
Inexpensive & Widely Available

• Modem - a device
that sends and
receives data over
telephone lines to and
from computers

• There are two types
of modems – internal
and external

High-Speed Phone Lines: More
Expensive but Available in Most Cities

•ISDN - hardware and software that allows
voice, video, and data to be communicated
over traditional copper-wire telephone
lines

•DSL - uses regular phone lines like ISDN, a
DSL modem, and special technology to
transmit data in megabits per second.

•T1 - a traditional trunk line that carries 24
normal telephone circuits and has a
transmission rate of 1.5 Mbps.

Wireless Systems: Satellite & Other
Through-the-Air Connections

• Communications satellite: a space station
that transmits radio waves called
microwaves from earth-based stations.

• Other wireless connections: towers
transmit radio waves. They can send data
up to the speed of 155 Mbps. Used to
operate local cellular phones.

2.2 Choosing Your Internet
Service Provider (ISP)
• ISP - a company that
connects you through
your communications
line to its servers, or
central (host)
computer, which
connect you to the
internet via another
company’s network
access points

2.3 How Does the Internet Work?
1. You connect to the ISP’s POP using a
telephone number that your ISP provides. A
point-of-presence (POP) is a collection of
modems and other equipment in a local area.

2. ISPs connect to a backbone to access remote
web servers. Backbones are high-speed, high
capacity transmission lines that use newest
communications technology.

TCP/IP, the Internet Society, and ICANN
Protocol is a set of conventions that
govern the format of data
transmitted electronically. They
ensure that all data is exchanged in
a consistent format.
TCP/IP is a protocol that enables all
computers to interpret and use data
transmitted over the internet.

ISOC (Internet Society) provides leadership in addressing
issues that confront the future of the internet.
ICANN was established to regulate human-friendly internet
domain names

2.4 Sending & Receiving Email

Incoming email (POP3) is stored
on a mailbox on the server.

Outgoing email is sent to a
Simple Mail Transfer Protocol
(SMTP) server.

Email Software & Carriers
• Get an email program
(browser) as part of
other computer
software

• Get email software as
part of your ISP package

• Get free email services

• Buy email software

Parts of an Email Message and
Attachments
•The three parts of an email
message are the (1) address of
the recipient, (2) subject of the
message, and (3) message
content.(4) attachment file.
(5) Signature

•In addition, the files on a
computer can be attached to an
email message.

•The person receiving the
attachment must have the same
software that created the
attachment.

Other Ways of
Communicating
• Instant messaging (IM) - • Mailing Lists: Email-based
allows any user on a given discussion groups
email system to send a
message and have it pop up
instantly on the screen of
anyone else logged onto • Listserv – is an automatic
that system mailing-list server that
sends email to subscribers
participating in discussion
topics

Netiquette: Appropriate Online
Behavior
 Consult FAQs
Do not send huge file
attachments
 Avoid flaming
Quote with relevant
 Do not SHOUT portion, when replying

Do not ―overforward‖
 Be careful with jokes

 Avoid sloppiness

Emoticons

Spam: Unwanted Junk Email
•Delete without opening the message
•Never reply to a spam message!
•Enlist the help of your ISP or use spam filters
•Fight back

2.5 The World Wide Web
• Q: What makes
the Web
graphically
inviting?
• A: Multimedia

• Q: What makes
the Web easily
navigable?
• A: Hypertext

The Web & How It Works
A computer with a domain name is called a website Example:
www.alislam.com

Web pages – the documents on a website
A web page is a document on the World Wide
Web that can include text, pictures, sound, and
video.

Web browser - software that enables users to
view web pages and to jump from one page to
another

Chrome, Firefox, Opera, Microsoft Internet
Explorer and Netscape Navigator are most
commonly used browsers

The Web & How It Works

•URLs – addresses for web pages

The URL is a string of characters that points to a specific piece
of information anywhere on the web

The URL consists of the web protocol, the name of the web
server, the directory on that server, and the file within that
directory

Using Your Browser to
Get Around the Web

The five basic elements
of a web browser are:

 Menu bar
 Toolbar
 URL bar
 Workspace
 Status bar

Using Your Browser to Get Around the Web
• Starting out from home – the start up page is the
home page
• Personalizing your home page – a home page can
be personalized according to the user’s choices
• Getting around – Back, Forward, Home, and
Search features
History list - allows you to return to a page you
have recently visited
Bookmarks or favorites – let you store the URL of
web pages you frequently visit so that you do not
have to remember or retype the URLs

Using Your Browser to Get Around the Web

• Interactivity – hyperlinks, radio buttons, and fill-in
text boxes
• Radio buttons – little circles located in front of
various options; selecting an option with the mouse
places a dot in the corresponding circle
Scrolling – Navigating up and down a web page using
scroll arrows
Frames are independently controllable sections on a
web page.They allow looking at the two pages
simultaneously.

Web Portals: Starting Points for Finding Information
• Web portal – a gateway website that offers a
broad array of resources and services, such as:

– online shopping malls
– email support
– current news and weather stock quotes
– travel information
– links to other popular subject categories

• Examples – www.itbpiksi.ac.id; www.google.com

Four Types of Search Engines

•Human-organized search sites

•Computer-created search sites

•Hybrid search sites

•Metasearch sites

Tips for Smart Searching
Choose search items well with the correct spelling
Use phrases with quotation marks
Put unique words first in a phrase
Use operators
Use wildcards
Read the Help or Search Tips section
Try an alternate general search site or a specific
search site

Multimedia on the Web
•Plug-in – a program that adds a specific feature to a
browser, allowing it to play or view certain files
•Developing multimedia – applets, Java, and Visual
Studio.NET
•Text and images
•Animation

•Video

• Download and view

• Streaming video

•Audio

•Download and listen

•Streaming audio

Push Technology & Webcasting
•Push technology - software that
automatically downloads information to
your computer
•Webcasting – a result of push technology,
where customized text, video, and audio
are sent automatically on a regular basis

The Internet Telephone & Videophone
Internet telephony - using the Net to make phone
calls, either one-to-one or for audio conferencing
VOIP software – Netmeeting, Skype, G+, YM, etc.

Designing Web Pages
There are professional
web designers who
develop websites.

Menu-driven programs,
such as Microsoft
FrontPage or Macromedia
Dreamweaver can be used
to design websites.

Permit & Declaration
End-user process Supporting
Services
Input Interface
Browser
Business
Services

Keuangan &
Small Medium
Kesehatan Pendidikan Sektor Transportasi
Business
Architecture System

perbankan
Profile
Application

System
Services

Directory Authentication Workflow ERP
and Authorization Management E-mail
Management System
(Non Ops )

SSL
Software
Support

Web Application
Server Server
Hierarchical Storage Management
Management
Platform and
Database

Operating System Relational
DBMS

Considerations: Resiliency, Scalability, Flexibility, Modularity

WebServer WebEditor
WYSIWYG editors
WYSIWYM editors

Languange
HTML, JavaScript, CSS, Perl, Python,
Ruby, PHP, Java, ASP, .NET, .NET MVC

Operating System WebHosting
cPanel, DirectAdmin, Domain
Technologie Control, Froxlor, GNUPanel,
H-Sphere, InterWorx, ISPConfig, ispCP,
Kloxo, Plesk, SysCP, Usermin, Webmin

2.6 The Online Gold Mine: More Internet Resources
•More internet resources:
•FTP (File Transfer Protocol) – for
copying all the free files you want
• Telnet – to connect to remote
computers
More Internet Resources
Newsgroups – for online typed
discussions on specific topics
Real-time chat – typed discussions
among online participants
Telnet: a protocol that allows you to
connect to remote computers on the
internet by using a user name and a
password and to run programs on
those computers.
FTP: a protocol that allows

Your Personal Cyberspace
•Blogs – web logs, accessible to other users
•Relationships – online matchmaking
•Education – distance learning
•Health – patient self-education
•Entertainment – amusing yourself on the
internet
Trade and Commerce
• E-commerce
• Auctions – linking individual buyers and sellers

• Online finance – trading, banking, and e-money

• Online job hunting

• B2B commerce

Session 2
Chapter 3 Application Software
3.1 Application Software: For Sale, for Free, or for Rent
3.2 Common Features of Software
3.3 Word Processing
3.4 Spreadsheets The Basics: How Spreadsheets Work
3.5 Database Software
3.6 Specialty Software

Chapter 4 System Software
4.1 The Components of System Software
4.2 The Operating System: What It Does
4.3 Other System Software:
4.4 Common Operating Systems Desktop & Laptop Operating Systems

Chapter 5 Hardware
5.1 Microchips, Miniaturization, & Mobility
5.2 The System Unit The binary system has only two digits - 0 and 1
5.3 Future Developments in Processing
5.4 Introduction Memory
5.5 Secondary Storage
5.6 Future Developments in Storage


Chapter 3
Application Software

3.1 Application Software: For Sale, for Free, or for Rent
•Commercial software – copyrighted and must be
paid for
•Public-domain software – not copyrighted
•Shareware - copyrighted and free but requires a fee
to be paid for continued use.
•Freeware - Copyrighted and free
•Rentalware – Copyrighted and leased
•Pirated software – Software obtained illegally
•Abandonware – Software that is no longer sold or
supported by its publisher

Tutorials & Documentation

•Tutorial - an instruction book or program that
helps you learn to use the product by taking you
through a prescribed series of steps

•Documentation - information that describes a
product to users. For example, a user guide or
reference manual

A few facts about Files and the Usefulness of
Importing & Exporting
A file is a collection of data or programs that
exist in a computer’s secondary storage.
Three well-known types of data files are:

•Document files; doc, docx, txt, rtf, pdf List File Format Extension
•Worksheet files; xls, xlsx,
•Database files; mdb, dbf List File Useful Software

Exchanging files between programs:
•Importing
•Exporting

Types of Application Software

Productivity software - software whose purpose is to
make users more productive at particular tasks
Examples:

• Word processing programs
• Spreadsheets
• Database managers

3.2 Common Features of Software

•User interface - the user-controllable display screen
that allows you to communicate, or interact, with the
computer
•A User can interact with the display screen using a
keyboard or a mouse
•Interacting with the user interface
•Special-purpose keys - used to enter, delete, and
edit data and to execute commands
•Function keys - used to execute commands specific
to the software being used

The GUI
• Graphical user interface (GUI) - allows users to use a
mouse or keyboard strokes to select icons and
commands from menus
• The three features of GUI are desktop, icons, and
• menus

Desktop, Icons & Menus

Desktop - the system’s main interface
screen, which displays pictures that
provide quick access to programs and
information

Menu - a list of options to choose from--a list of
commands for manipulating data
Pull-down menu - a list of options that pulls down from
the menu bar at the top of the screen
Cascading menus - menus that seem to fly back to the
left or explode out to the right

Pull-down menu
Pull-down menu

• Pull-up menu - a list of
options that pulls up
from the menu bar at
the bottom of the screen

• Pop-up menu - a list of
command options that
can “pop up” anywhere
on the screen when you
click the right mouse
button

Documents, Toolbars, & Windows
• Title bar - A bar that runs across the very top
of the display window and shows the name of
the folder you are in

• Menu bar – a bar that shows the names of the
various pull-down menus available

Documents, Toolbars, & Windows

• Toolbar - A bar that displays menus and icons
representing frequently used options or
commands

• Taskbar – the bar across the bottom of the
desktop screen that contains the Start button and
that appears by default

• Window – A rectangular frame on the display
screen, through which files of data and
application programs can be viewed

The Help Command
• Help
command - a
command
generating a
table of
contents, an
index, and a
search
feature that
can help you
locate
answers

3.3 Word Processing

• Word processing software - allows users to
use computers to create, edit, format, print, and
store text material

• Creating Documents
• Creating a document - entering text using the
keyboard or the dictation function associated
with speech recognition software

Word processing software features
• Cursor - the movable
symbol on the display
screen that shows you
where you may next
enter data or commands
Scrolling - moving quickly
upward, downward, or
sideways through the text
or other screen display
• Word Wrap – automatically continues
text to the next line when you reach the
right margin

Editing Documents

• Insert and delete – To add to the document
using the insert key and remove text using the
delete or backspace key

• Undo – To restore text that has been deleted

• Find and replace – To find existing words,
phrases, or numbers and replace them with
something else

• Cut/Copy and paste - To cut or copy text and
move it to the clipboard and transfer the material
to an existing or new document

Editing Documents

• Spelling checker - To test incorrectly
spelled words

• Grammar checker - To highlight poor
grammar, wordiness, incomplete sentences,
and awkward phrases

• Thesaurus - To present users with the
appropriate word or alternative words

Formatting Documents with the Help of Templates &
Wizards
•Formatting - determining the appearance of a
document

•Template - a preformatted document that provides
basic tools for shaping a final document

•Wizard - answers your questions and uses the
answers to lay out and format a document

Formatting Documents

• Font - typeface and type
size

Spacing and columns: Margins and justification:
• Left margin
• Single-spaced
• Right margin
• Double-spaced • Top margin
• One-column • Bottom margin
• Two columns • Justification
• Several columns • Left-justification
• Centering

Formatting Documents

Headers, footers, and page Other formatting:
numbers: • Borders
• Shading
• Header
• Tables
• Footer
• Footnotes
• Page numbers
• Graphics
• Clip art

Printing, Faxing, or Emailing Documents

• Printing:
• Individual pages
• Range of pages
• Previewing - Viewing a document before it’s printed

Saving Documents

Saving - storing or preserving a document as an
electronic file permanently

Tracking Changes & Inserting Comments

• Editing changes can be tracked by
highlighting them, underlining additions, and
crossing deletions

• Comments or questions can be inserted
into the documents

3.4 Spreadsheets
The Basics: How Spreadsheets Work

A spreadsheet is organized as:
•Lettered column headings across the top
•Numbered row headings down the left side
•Labels - descriptive text that identifies categories
Where columns and rows meet:
• Cell - the place where a row and a column intersect
– Cell address - position of a cell
– Range - a group of adjacent cells
– Value - data entered in a cell
• Cell pointer - indicates where data is to be entered


Why the spreadsheet has become so popular:
• Formulas - instructions for calculations
• Functions - built-in formulas to perform common
calculations
• Recalculation - process of recomputing values
• What-if analysis

Using worksheet templates:
• Worksheet templates - forms containing formats and formulas
custom-designed for particular kinds of work
• Multidimensional spreadsheets – one spreadsheet can be
linked to another

Analytical graphics - graphical forms that make
numeric data easy to analyze

http://google.com/analytics/

http://www.google.com/publicdata/

3.5 Database Software
Database – “a collection of interrelated files”
• Database software - a program that sets up and controls the
structure of a database and access to the data
Benefits of Database Software:
• Reduced redundancy
• Increased integrity
TIMELINE DATABASE MANAGEMENT SYSTEMS

The Basics: How Databases Work
How a relational database is organized:
• Tables of rows and columns
• Row (record) - example: a person’s address
• Column (field) - example: the person’s last name

How various records can be linked:
Finding what you want:
• Key field - a field that is used to
sort data • Querying - locating and
• Primary key - holds a unique displaying records
value for each record
• Foreign key - used to cross-
reference data among relational
tables

The Basics: How Databases Work
Sorting and analyzing Putting search results to use:
records and applying
formulas: • Saving
• Formatting
• Sorting data - • Printing
alphabetically, • Copying
numerically, • Transmitting
geographically, or in
some other order

Personal Information Managers Free and open-source collaborative software

Personal information can include any of the
Bongo · Buni Meldware · Citadel ·
following: Client-Server DAViCal · Kolab · OpenGroupware.org ·
•Personal notes/journal Open-Xchange · Scalix · Zimbra · Zarafa
•Address books
•Lists (including task lists)
•Significant calendar dates Citadel · eGroupWare · Group-Office ·
•Birthdays Horde · KnowledgeTree · Kolab · Feng
Web based Office Community Edition ·
•Anniversaries phpGroupWare · ProjectPier · Simple
•Appointments and meeting Groupware · Tine 2.0
•Reminders
•Email, instant message archives
•Fax communications, voicemail Personal information Evolution · Kontact · Spicebird · Mozilla
managers Sunbird · Mozilla Thunderbird/Lightning
•Project management features
•RSS/Atom feeds
•Alerts
•References (including scientific references,
websites of interest)

3.6 Specialty Software
• Presentation
graphics software -
uses graphics,
animation, sound,
and data or
information to
make visual
presentations

Presentation Graphics Software

• Presentation-graphics programs offer
templates to help organize presentations.

• Templates are of two types:

– Design templates - offer formats, layouts,
background patterns, and color schemes that
can apply to general forms of content material

– Content templates - offer formats for specific
subjects

Financial Software
• Financial software - a growing category that ranges from personal-
finance managers to entry-level accounting programs to business
financial-management packages
•

Microsoft Money

Desktop Publishing (DTP)
• DTP involves mixing text and graphics to produce high-quality output for
commercial printing, using a microcomputer and mouse, scanner, laser or
ink-jet printer, and DTP software.

•

Drawing & Painting Programs
• Drawing program -
graphics software that
allows users to design
and illustrate objects and
products

• Painting program - Vector image
graphics program that
allows users to simulate
painting on screen

Raster
image

Other Specialty Software

•Web page design/authoring software – used to create web pages with
sophisticated multimedia features.

•Video editing software allows you to import video footage to a PC and
edit it.
•Audio editing software provides capabilities to work with sound tracks,
clean up background noise, and emphasize certain sound qualities.

•Project management software -
•Computer-Aided Design (CAD) software -
•Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM)
software -


Chapter 4
System Software

4.1 The Components of System Software
• Operating system -
the principal
component of
system software

• Device drivers -
help the computer
control peripheral
devices

• Utility programs -
support, enhance,
or expand existing
programs

4.2 The Operating System: What It Does
• Booting - the process of loading an operating
system into a computer’s main memory

The Operating System: What It Does

User interface - user-controllable display screen
that allows one to communicate, or interact, with
a computer

CPU Management

Supervisor (kernel) - program which remains in
main memory while the computer is running,
and directs other ―nonresident‖ programs to
perform tasks that support application programs

File Management and Formatting

•The operating
system’s file system
arranges files in
hierarchical fashion

•Formatting or
initializing a disk is the
process of preparing
that disk for use

Task Management
Number of Number of Order of
Users Processors Processing
Multi-tasking One One Concurrently

Multi- Multiple One Concurrently
programming
Time sharing Multiple One Round robin

Multi- One or more Two or Simultaneously
processing more

Processing of two or more programs

4.3 Other System Software:
Device Drivers & Utility Programs
• Device drivers -
specialized
software
programs that
allow input and
output devices
to communicate
with the rest of
the computer
system

Utilities: Service Programs
•Backup utility - program which makes a duplicate copy
of the information on your hard disk
•Data-recovery utility - program which restores data
that has been physically damaged or corrupted

•Antivirus software - program that scans hard disks, floppy
disks, and memory to detect viruses

•Data compression utility - program which removes
redundant elements, gaps, and unnecessary data from a
computer’s storage space so that less space (fewer bits) is
required to store or transmit data

• Fragmentation - the
scattering of portions of
files about the disk in
nonadjacent areas, thus
greatly slowing access to
the files

• Defragmenter utility -
program that finds all the
scattered files on a hard
disk and reorganizes them
as contiguous files


• Disk scanner and disk
cleanup utilities:

• Detect & remove
unnecessary files

• Detect & correct
disk problems

4.4 Common Operating Operating system

Systems History · Timeline · List · Comparison · Usage share · Development ·
General
Desktop & Laptop Operating Advocacy

Systems Kernel
Architectures
General Monolithic kernel · Microkernel
Subtypes Exokernel · Nanokernel · Hybrid
Components User/Kernel space · Server · Loadable kernel module · Device driver

Process management
• Platform - a particular Concepts
Process · Process control block · Interrupt · Thread · Context switch ·
processor model and Scheduling
operating system on CPU modes Protected mode · Supervisor mode
which a computer system
is based Scheduling
Cooperative multitasking · Preemptive multitasking · Round-robin
scheduling · Fixed priority pre-emptive scheduling · Multilevel
• Disk Operating System algorithm
feedback queue · Shortest job next
(DOS) - the original
Memory Memory protection · Segmentation · Paging · Segmentation fault ·
operating system management General protection fault · Bus error
produced by Microsoft,
which had a hard-to-use Examples
AmigaOS · BeOS · BSD · DOS · GNU · Linux · Mac OS · MorphOS ·
OS/2 · ReactOS · Solaris · Unix · Windows · more...
command-driven user
interface Miscellaneous Boot loader · Live CD · Live USB · PXE · API · Virtual file system ·
concepts Virtual tape library · Computer network · CLI · TUI · GUI · VUI · HAL

Desktop & Laptop Operating Systems
• Mac OS - operating system which runs only on
Apple Macintosh computers

Desktop & Laptop Operating Systems
•Microsoft Windows 3.X - released in 1992;
simply a layer over DOS

•Microsoft Windows 95/98 - successors to
3.X

Plug and Play - the ability of a computer to
automatically configure a new hardware
component that is added to it

•Microsoft Windows Me (WinMe) -
Millennium Edition

Network Operating Systems

•Novell’s Netware - a popular
network operating system for
coordinating microcomputer-
based local area networks (LANs)
•Windows NT - Microsoft’s multitasking OS
which allows multiple users to share resources
such as data and programs

•Windows 2000 - successor to Windows NT

• Windows XP - Microsoft’s newest OS, which combines
elements of Windows 2000 and Windows Me

New GUI of Windows XP

Microsoft .NET

• A set of Microsoft software technologies for
connecting information, people, and
systems through the use of special building
block web service programs.

• Web services programs are created using
XML a web-document tagging format.


•UNIX - a multitasking operating
system for multiple users with built-
in networking capability and versions
AIX, HP-UX, IRIX, Linux, that can run on all kinds of
Minix, Ultrix, Xenix.
computers

• Sun Microsystems’ Solaris

• Berkeley Software Distribution
(BSD)

• Linux - a free version of UNIX, with continual
improvements resulting from the efforts of tens of
thousands of volunteer programmers

• Linux - Open-source
software - software
which any
programmer can
download from the
Internet for free and
modify with
suggested
improvements

Linus Torvalds,
creator of Linux

Operating Systems for Handhelds
• Palm OS - the dominant
OS for handhelds, which
runs the Palm and
Handspring Visor, and is
licensed to other
companies

• Windows CE (now
Pocket PC) - slimmed-
down version of
Windows for handhelds

Embedded Systems
• An embedded system is any electronic system
that uses CPU chip

• It is a specialized computer system that is a
part of a larger system

• Used extensively in cars, space vehicles, cell
phones, PDAs, and robots

• Many companies have formed the non-profit,
vendor neutral Embedded Linux Consortium
to make Linux a top OS of choice

4.5 The OS of the Future:
Web Services Platform

•Web services allow describing, identifying, and
communicating data over the WWW in a consistent
fashion that can be read by many different types of
machines

•Microsoft .NET delivers web services

•Competitors concentrating on middleware as an answer

Open Source Computing

•Distributed system - a non-centralized network
consisting of several computers and other
devices that can communicate with one another

•Gaining ground in foreign countries, small
companies, and schools


Chapter 5
Hardware: The CPU

5.1 Microchips, Miniaturization, & Mobility

From Vacuum Tubes to Transistors to Microchips

• Transistor - a tiny
electrically
operated switch, or
gate, that can
alternate between
“on” and “off”
many millions of
times per second

1940s vacuum tube towering
over 1950s transistor

Miniaturization Miracles: Microchips,
Microprocessors, & Micromachines
• Microchips store and process data in all the
electronic
• gadgetry

• A microprocessor is the miniaturized circuitry of a
• computer processor

5.2 The System Unit

The Binary System: Using On/Off Electrical States
to Represent Data & Instructions
• The binary system has only two
digits - 0 and 1

• Bit - binary digit

• Byte - group of 8 bits used to
represent one character, digit, or
other value

The Binary System: Using On/Off
Electrical States to Represent Data &
Instructions
• Kilobyte 1000 bytes

• Megabyte 1,000,000 bytes (one million)

• Gigabyte 1,000,000,000 bytes (one billion)

• Terabyte 1 trillion bytes

• Petabyte 1 quadrillion bytes

The Binary System: Using On/Off Electrical
States to Represent Data & Instructions

• ASCII - the binary code most
widely used with
microcomputers

• EBCDIC - used with large
computers

• Unicode - uses two bytes for
each character rather than
one byte (8 bits)

Machine Language

Machine language - a binary-
type programming language
built into the CPU that the
computer can run directly

The Computer Case: Bays, Buttons &
• Bay - a shelf or
Boards
opening used for
the installation of
electronic
equipment
• System unit -
houses the
motherboard,
power supply, and
storage devices
• Case – the empty
box with just power
supply Overhead view of system unit

Power Supply
• Power supply - a device that converts AC to DC to run the
computer

• Expansion – a way of increasing a computer’s capabilities
by adding hardware to perform tasks beyond the scope of
the basic system

• Motherboard - the main circuit board in the system unit

The Motherboard & the CPU TECHNOLOGIES
Microprocessor Chip ISA : CISC · EDGE · EPIC · MISC · OISC ·
RISC · VLIW · NISC · ZISC · Harvard
architecture · von Neumann
Architecture architecture · 4-bit · 8-bit · 12-bit · 16-
bit · 18-bit · 24-bit · 31-bit · 32-bit · 36-
Two principal architectures or designs of bit · 48-bit · 64-bit · 128-bit ·
microprocessors: Comparison of CPU architectures

1 CISC (Complex Instruction Set Parallelism
Computing) - Supports a large number
of instructions at relatively low Instruction pipelining · In-order & out-
Pipeline of-order execution · Register renaming ·
processing speeds Speculative execution · Hazards

2 RISC (Reduced Instruction Set Level
Bit · Instruction · Superscalar · Data ·
Computing) - Used mostly in Task
workstations, a great many seldom- Multithreading · Simultaneous
Threads multithreading · Hyperthreading ·
used instructions are eliminated. Superthreading
Flynn's
SISD · SIMD · MISD · MIMD
taxonomy

The Motherboard & the
Microprocessor Chip
Two kinds of microprocessors used in most personal computers
today:

1 Intel-type chips made by Intel, AMD, and others

2 Motorola-type chips made by Motorola for Apple Macintosh
computers

Processing Speeds: From Megahertz to
Picoseconds
Micro- Super-
Workstations Mainframes
computers computers

Megahertz &
X
Gigahertz

MIPS X X

FLOPS X

Fractions of a
second
X X X X

How the
Processor
or CPU
works:
Control
Unit, ALU,
& Registers

How Memory Works: RAM, ROM,
CMOS, & Registers
The CPU follows the instructions of the
software to manipulate data into information.
The CPU consist of:

• The control unit – for directing electronic signals
• The arithmetic/logic unit – for arithmetic and logical
operations and to control the speed of those
operations

CMOS, & Flash
Types of memory chips:
1 RAM – to temporarily store program
instructions and data
2 ROM – to store fixed start-up instructions
3 CMOS – to store flexible start-up
instructions
4 Flash – to store flexible programs

How Cache Works: Level 1 (Internal) &
Level 2 (External)
•Cache - temporary storage for instructions and data
that the processor is likely to use frequently, thus
speeding up processing

•Level 1 (L1) cache – part of the processor chip

•Level 2 (L2) cache – is not part of the microprocessor
chip

•Virtual memory - free hard-disk space used to extend
the capacity of RAM

Ports & Cables
•A port is a connecting socket or jack on the outside of
the system unit into which are plugged different kinds
of cables.
1.Serial port - sends bits one at a time, one after
another
2.Parallel port
3.SCSI port
4.USB port
5.FireWire port
6.6Dedicated port
7.Infrared port

Ports & Cables
1. Serial port
2. Parallel port -
transmits 8 bits
simultaneously
3. SCSI port
4. USB port
5. FireWire port
6. Dedicated port
7. Infrared port

Ports & Cables
1. Serial port
2. Parallel port
3. SCSI port - allows
data to be
transmitted in a
“daisy chain” to up
to 7 devices
4. USB port
5. FireWire port
6. Dedicated port
7. Infrared port

Ports & Cables
1. Serial port
2. Parallel port
3. SCSI port
4. USB port - can theoretically
connect up to 127
peripheral devices daisy-
chained to one general-
purpose port
5. FireWire port
6. Dedicated port
7. Infrared port

USB port and connector

Ports & Cables
1. Serial port
2. Parallel port
3. SCSI port
4. USB port
5. FireWire port – for camcorders, DVD
players, and TVs
6. Dedicated port
7. Infrared port

Ports & Cables

1. Serial port
2. Parallel port
3. SCSI port
4. USB port
5. FireWire port
6. Dedicated port -
special-purpose
ports
7. Infrared port
Dedicated ports: mouse port,
modem port, and keyboard port

Ports & Cables
1. Serial port
2. Parallel port
3. SCSI port
4. USB
5. FireWire port
6. Dedicated port
7. Infrared port - allows a computer to make a cableless
connection with infrared-capable devices

Expandability: Buses & Cards
• Expansion slots -
sockets on the
motherboard into
which you can plug
expansion cards

• Expansion cards -
circuit boards that
provide more
memory or that
control peripheral
devices

•ISA bus - for ordinary low-speed
uses; the most widely used
expansion bus
•PCI bus - for higher-speed uses;
used to connect graphics cards,
sound cards, modems, and high-
speed network cards
•AGP bus - for even higher speeds
and 3D graphics

•Graphics cards - for monitors

•Sound cards - for speakers and audio output

•Modem cards - for remote communication via
phone lines

•Network interface cards - for remote
communication via cable

•PC cards - for laptop computers

5.3 Future Developments in Processing
•Selling processing power over the internet
•Combining functions on a single chip
•Nanotechnology
•DSP chips: Processors for the Post-Pc Era
•Optical Computing
•DNA Computing
•Quantum Computing
•Other Possibilities: Molecular & Dot Computers


Chapter 5
Hardware: Storage

Hardware: The CPU & Storage
How to Buy a Multimedia Computer
System


5.6 Future Developments in Storage


•How Memory Works: RAM, ROM, CMOS, & Registers

•The CPU follows the instructions of the software to
manipulate data into information.

CMOS, & Registers
The CPU consist of:

•The control unit – for directing electronic signals

•The arithmetic/logic unit – for arithmetic and logical operations and to
control the speed of those operations

CMOS, & Flash

• Types of memory chips:

1 RAM – to temporarily store program instructions
and data
2 ROM – to store fixed start-up instructions
3 CMOS – to store flexible start-up instructions
4 Flash – to store flexible programs


Floppy Disks

• Floppy disk - a removable flat piece
of mylar plastic packaged in a 3.5-
inch plastic case

Floppy-Disk Cartridges

• Zip disks – 100, 250,
Zip
or 750 megabytes disk

• 3.5-inch floppy disks –
1.44 megabytes
Floppy
disk

Hard Disks
• Hard disks - thin but
rigid metal, glass, or
ceramic platters
covered with a
substance that
allows data to be
held in the form of
magnetized spots

Hard Disks

• Head crash - An event that happens when the surface of
the read/write head or particles on its surface come into
contact with the surface of the hard-disk platter, causing
the loss of some or all of the data on the disk.

Hard Disks

Nonremovable
hard disks -
housed in a
microcomputer
system unit and
used to store
nearly all
programs and
most data files

Hard Disks

• Removable hard disks
- one or two platters
enclosed along with
read/write heads in a
hard plastic case,
which is inserted into
Bits on disk - dark stripes are 0
a microcomputer’s bits and bright stripes are 1 bits
cartridge drive

Optical Disks: CDs & DVDs
• Optical disk - a
removable disk
on which data is
written and read
through the use
of laser beams

• CD-ROM - read
only. For pre-
recorded text,
graphics, and
sound

• CD-R - for
recording on once

• CD-RW - for
rewriting many
times


• DVD-ROM - for reading only

• DVD-R - for recording on once

• For rewriting many times:

• DVD-RW
• DVD-RAM
• DVD+RW

Magnetic Tape

• Magnetic tape - thin plastic
tape coated with a
substance that can be
magnetized (for 1s) or left
non-magnetized (for 0s)
Magnetic tape
• Tape cartridges - modules
resembling audio cassettes
that contain tape in
rectangular, plastic housings

Tape cartridge

Smart Cards
• Smart card - looks
like a credit card but
contains a
microprocessor
embedded in the
card

• Optical card - plastic,
laser-recordable,
wallet-type card Smart card
used with an optical-
card reader

Flash Memory Cards
• Flash memory card - circuitry on
credit-card-size PC card that can
be inserted into slots connecting
to the motherboard on notebook
computers
• Solid State Disk/Drive

• Online Secondary Storage
• @Backup
• Connected Online Backup

5.6 Future
Developments in
Storage
Higher-density disks
Molecular electronics
Solid State Disk
Sci-Fi Disk Future:
• Carbon Nanoballs
• Molecular memory:
• Bacteria
• Quantum mechanics:

Chapter 6 Hardware: Input
Session 3
6.1 Input & Output
6.2 Input Hardware
6.3 Input Technology & Quality of Life: Health & Ergonomics
6.4 Input & Output
6.5 Output Hardware
6.6 Mixed Output: Sound, Voice, and Video

Chapter7 Networks&Communications
7.1FromtheAnalogtotheDigitalAge
7.2ThePracticalUsesofCommunications
7.3CommunicationsMediaandTransferRates
7.4TransmittingData-Behind-the-ScenesDetails
7.5Networks
7.6TheFutureofCommunications
7.7Cyberethics

Chapter8 Files,Databases,&E-Commerce
8.1ManagingFiles:BasicConcepts Datastoragehierarchy-levelsofdatastoredinacomputer:
8.2DatabaseManagementSystems
8.3DatabaseModels
8.4FeaturesofaDatabaseManagementSystem
8.5Databases&theNewEconomy:E-Commerce,DataMining,&B2BSystems
8.6EthicsofUsingDatabases:ConcernsaboutAccuracy&Privacy


Chapter 6
Hardware: Input

6.1 Input & Output

Input hardware -
devices that translate
data into a form the
computer can process

6.2 Input Hardware
• Keyboard - a device
that converts letters,
numbers, and other
characters into
electrical signals that
can be read by the
computer’s processor

Braille keyboard

Keyboards
• Traditional computer
keyboards

• Specialty keyboards and
terminals

 Dumb terminals
 Intelligent terminals
 Internet terminals
Dumb terminal

Keyboards
Specialty keyboards and terminals:

Dumb terminal:
• Airline reservations

Intelligent terminal: Point-of-sale (POS) terminal
• Automatic teller machine (ATM)
• Point-of-sale (POS) terminal

Internet terminal:
• Set-top box
• PDA

Pointing Devices

• Pointing devices - control
the position of the
cursor or pointer on the
screen

• Mouse
• Trackball
• Pointing stick
• Touchpad
Mouse for a right-handed user

Pointing Devices

• The mouse and its
variants:
•
• Mouse
• Trackball
• Pointing stick
• Touchpad Ergonomic trackball

Pointing Devices

variants:
•
• Mouse
• Trackball
• Pointing stick
Touchpad Pointing stick

Pointing Devices

variants:
•
• Mouse
• Trackball
• Pointing stick
Touch pad
• Touchpad

Pointing Devices

Touch screens

Pointing Devices
• Pen input:

• Pen-based computer
system - allows users
to enter handwriting
and marks onto a
computer screen by
means of a penlike
stylus rather than by
typing on a keyboard
Pen-based computer

Pointing Devices
• Pen input:

• Light pen - a light-
sensitive penlike
device that uses a
wired connection to
a computer terminal
Light pen

Pointing Devices
• Pen input:

• Digitizer -
converts
drawings and
photos to digital
data using a
mouselike device Digitizing tablet

called a puck

Scanning and Reading Devices
• Source data-entry
devices – create
machine-readable
data

• Scanners - use light-
sensing equipment to
translate images of
text, drawings,
photos, and the like
into digital form

Bar-code readers:
• Barcodes - photoelectric
scanners that translate the
symbols in the bar code into
digital code
• Quick Response code (QR) is
a type of matrix barcode (or
two-dimensional code) first
designed for the automotive
industry.


Mark-recognition and character-recognition devices sense
marks or characters

• MICR - character recognition system that uses magnetic
ink and special characters

• OMR

• OCR


Mark-recognition and character-
recognition devices:

• MICR

• OMR - uses a device that reads
bubble marks and converts them
into computer-usable form

• OCR

Mark-recognition and
character-recognition devices:

• MICR

• OMR

• OCR - converts scanned text
from images to an editable
text format that can be
imported into a word
processing application and
manipulated

• Fax machine – scans an image and
sends it as electronic signals over
telephone lines to a receiving fax
machine

• Types of fax machines:

• Dedicated fax machine

• Fax modem
•

Dedicated fax machine

Source Data-Entry Devices

• Types of fax machines:

• Dedicated fax machine

• Fax modem

Fax modem circuit board

Audio-Input Devices

• Audio-input device - records analog sound and translates
it for digital storage and processing

• Digitizing an audio signal:

• sound board

• MIDI board

Webcams & Video-Input Cards

• Webcam – a video camera attached to a
computer to record moving images that
can be posted on a website in real time

• Video cards:

• Frame-grabber video card
•
• Full-motion video card

Digital Cameras
• Digital camera - uses
a light-sensitive
processor chip to
capture
photographic images
in digital form and
store them on a
small diskette Digital camera
attached to a computer

Speech-Recognition Systems

• Speech-recognition system - converts a
person’s speech into digital signals

Sensors

• Sensor – an input
device that collects
specific data
directly from the
environment and
transmits it to a
computer

Radio-Frequency Identification Tags
• RFID tags – based on
an identifying tag
bearing a microchip
that contains specific
code numbers RFID tag in a car for paying toll

A tollbooth with RFID readers

Human-Biology-Input devices
• Biometrics - the
science of measuring
individual body
characteristics
Palm print recognition reader

Screen of face recognition system

Towards More Input from Remote locations
•The linkage of computers and telecommunications
means that data may be input from nearly anywhere

•Toward More Source Data Automation

•Input technology is being designed to capture data at its
source to reduce the costs and mistakes associated with
copying or preparing data in a form suitable for
processing.
• Input help for the disabled
• More sophisticated touch devices

6.3 Input Technology & Quality of Life:
Health & Ergonomics

• Health Matters:
• RSIs
• Eyestrain & headaches
• Back & neck pains
• Electromagnetic fields
• Noise
Carpal tunnel syndrome

Ergonomics: Design with People in Mind

• Ergonomics - a field devoted to making working
conditions and equipment safer and more
efficient

Ergonomic keyboard


Chapter 6
Hardware: Output

6.4 Input & Output
• Output hardware
- devices that
translate
information
processed by the
computer into a
form that
humans can
understand

6.5 Output Hardware

•Softcopy - data that is
shown on a display
screen or is in audio or Hard
copy
voice form

•Hardcopy - printed Soft
output copy

Traditional Softcopy Output: Display Screens
• Display screens - output devices that show programming
instructions and data as they are being input and
information after it is processed


• Pixel (picture element) -
the smallest unit on the
screen that can be
turned on and off or
made different shades

Factors affecting screen clarity:

• Dot pitch (dp) - the amount of space
between the centers of adjacent pixels;
the closer the dots, the crisper the image

• Resolution - the image sharpness of a
display screen; the more pixels there are
per square inch, the finer the level of detail

• Color depth - the amount of information,
expressed in bits, that is stored in a dot

• Refresh rate - the number of times per
second that the pixels are recharged so
that their glow remains bright

Two types of monitors:

•CRT (cathode ray tube)- a vacuum tube
used as a display screen in a computer or
video display terminal
•Flat-panel display
PLASMA LCD
•Liquid crystal display (LCD)
•A plasma display
•Surface-conduction electron-emitter
display (SED)
•Digital Light Processing (DLP)
•An organic light-emitting diode (OLED)

Flat Panel
CRT

DLP SED OLED


Two types of monitors:
• CRT
• Flat-panel display - made up of two plates of
glass separated by a layer of a substance in
which light is manipulated

•Active-matrix versus passive-matrix flat-panel displays:
•Active-matrix display - each pixel on the screen is
controlled by its own transistor
•Passive-matrix


•Active-matrix versus passive-matrix flat-panel
displays:

•Active-matrix display

•Passive-matrix display - a transistor controls a
whole row or column of pixels


• Color & resolution standards for monitors:

Traditional Hardcopy Output: Printers

•Printer - an output device that prints
characters, symbols, and perhaps graphics on
paper or another hardcopy medium

•Dpi - a measure of the number of rows and
columns of dots that are printed in a square inch


•Impact printer - forms characters or images by
striking a mechanism such as a print hammer or
wheel against an inked ribbon, leaving an image
on paper

•Non-impact printer - forms characters and
images without direct physical contact between
the printing mechanism and paper


• Nonimpact printers:

• Laser printer - creates images on a drum which are
treated with a magnetically charged toner, and
then transferred from drum to paper

Replacing a laser toner cartridge


Nonimpact printers:

• Ink-jet printers - spray small,
electrically charged droplets of ink
from four nozzles through holes in a
matrix at high speed

• Thermal printers - use colored
waxes and heat to produce images
by burning dots onto special paper Ink-jet printer

• Plotter - a specialized output device designed
to produce high-quality graphics in a variety
of colors

• Multifunction printer - output device that
combines several capabilities, such as printing,
scanning, copying, and faxing

6.6 Mixed Output: Sound, Voice, and Video

•Sound output devices - produce digitized
sounds, ranging from beeps and chirps to music

•Voice output devices - convert digital data into
speech-like sounds

•Video output - photographic images which are
played at 15-29 frames per second to give the
appearance of full motion

Towards More Input from Remote locations

The linkage of computers and telecommunications means
that data may be input from nearly anywhere

Toward More Source Data Automation

Input technology is being designed to capture data at its
source to reduce the costs and mistakes associated with
copying or preparing data in a form suitable for
processing.
• Input help for the disabled
• More sophisticated touch devices

Toward More Source Data Automation
More refinements in source
data automation:
•Better speech recognition
•Smaller electronic cameras
•Pattern-recognition &
biometric devices
•Brainwave devices
Computer-read emotions

BIOMETRIC
BRAINWAVE SPEECH RECOGNITION

Toward More Output in Remote Locations
• Output in remote locations is the wave of the
future.
• As TV and the personal computer converge, you
can even have your PC continually receive any
websites covering topics of interest to you

Toward More Realistic Output
• Display screens - better and cheaper
• Audio - higher fidelity
• Video - movie quality for PC’s
• Three-dimensional display


Chapter 7
Networks & Communications

7.1 From the Analog to the Digital Age

•Analog - continuously varying in strength and/or
quality

•Digital - communications signals or information
represented in a two-state (binary) way using electronic
or electromagnetic signals

Purpose of the Modem - Converting
Digital Signals to Analog Signals & Back
Modem - short for modulate/demodulate
• Sending modem - modulates digital signals into analog signals for
transmission over phone lines
• Receiving modem - demodulates the analog signals back into digital
signals

7.2 The Practical Uses of Communications
Videoconferencing & Videophones
Videoconferencing - the use of television
video and sound technology as well as
computer to enable people in different
locations to see, hear, and talk with one
another
Workgroup Computing & Groupware
Workgroup computing also called collaborative
computing – teams of co-workers (often at
different sites) use networks of microcomputers to
share information and to cooperate on projects
Made possible by networks, microcomputers, &
groupware

Telecommuting
Telecommuting - working
at home while in
telecommunication
with the office

Virtual Offices

Virtual office - an often nonpermanent and
mobile office run with computer and
communications technology

Smart Television
•Digital television (DTV) - uses a digital signal, or
series of 0s and 1s

•High-definition television (HDTV) – works with
digital broadcasting signals and has higher-
resolution than standard television

•Standard-definition television (SDTV) - allows
broadcasters to transmit more information
within the HDTV bandwidth

7.3 Communications Media and Transfer Rates
Communications media – carries signals over a
communications path, the route between two
or more communications media services

Wired Communications Media - Wires
and Cables

Twisted-pair wire - two strands of
insulated copper wire, twisted around
each other

Wired Communications Channels
• Coaxial cable - insulated
copper wire wrapped in a
solid or braided metal shield,
then in an external cover

Wired Communications Channels
Fiber-optic cable - dozens or hundreds of thin strands of
glass or plastic that transmit pulsating beams of light
rather than electricity

Fiber-optic cable Fiber-optic strand

The Electromagnetic Spectrum, the
Radio Spectrum, & Bandwidth

Radio frequency spectrum

Wireless Communications Channels
• Infrared transmission - the transmission of
data signals using infrared-light waves

Broadcast radio - a wireless Microwave radio - transmits
transmission medium that sends voice & data through the
data over long distances-- atmosphere as super-high-
between regions, states, or frequency radio waves called
countries microwaves

Communications
satellites - microwave relay
stations in orbit around the
earth

Long-Distance Wireless
Communications
Global Positioning System
(GPS) - 27 earth-orbiting
satellites continuously
transmitting timed radio
signals that can be used
to identify earth locations
Car with GPS unit to
Pagers - simple radio receivers guide users
that receive data (but not voice
messages) sent from a special
radio transmitter

Long-Distance Wireless
Communications
• Analog cellphones (known as
1G- first generation) - designed
primarily for communicating by
voice through a system of
ground-area cells
Digital wireless services (2G) - support digital
cellphones & personal digital assistants by using
a network of cell towers to send voice
communications & data over the airwaves in
digital form
Broadband wireless digital services (3G) -
―always on‖ technology which can quickly
transmit video, still pictures, and music

Cellphone tower

Short-Range Wireless
Communications
•Bluetooth - a short-range wireless digital
standard aimed at linking cellphones, PDAs,
computers, & peripherals up to distances of
30 feet

•WiFi (wireless fidelity)- a short-range
wireless digital standard aimed at helping
portable computers and handheld wireless
devices to communicate at high speeds and
share internet connections at distances up
to 300 feet

Compression & Decompression -
Putting More Data in Less Space
•Compression - a method of removing repetitive elements from
a file so that the file requires less storage space and therefore
less time to transmit

• Lossless vs. lossy compression
• Compression standards

7.4 Transmitting Data - Behind-the-Scenes
Details

Factors Affecting Data Transmission

• Line configurations
• Point-to-point line - directly connects the
sending & receiving devices
• Multipoint line - a single line that interconnects
several communications devices to one computer
• Serial vs. parallel transmission
• Serial data transmission - bits are transmitted
sequentially, one after the other

Serial Data Transmission

Factors Affecting How Data Is
Transmitted
• Serial vs. parallel Parallel data transmission -
transmission bits are transmitted through
separate lines
simultaneously

Direction of transmission - simplex, half-duplex, and full-
duplex
Simplex transmission - data can travel in only one
direction

Transmitted
• Direction of transmission - simplex, half-
duplex, and full-duplex
• Half-duplex transmission - data travels in both
directions but only in one direction at a time

Full-duplex transmission - data is transmitted back and
forth at the same time

Transmitted
Transmission mode - asynchronous vs. synchronous
Asynchronous transmission - data is sent one byte at a
time, with each string of bits making up the byte and
bracketed with special control bits

Synchronous transmission - data is sent in blocks, with
start and stop bit patterns (synch bytes) at the beginning
and end of the blocks

Transmitted
•Circuit switching - transmitter has full use of the circuit
until all the data has been transmitted and the circuit is
terminated
•Packet switching - electronic messages are divided into
packets for transmission over a wide area network to their
destination, through the most expedient route

Multiplexing - transmission of multiple signals over a
single communications channel
Multiplexers
Concentrators
Front-end
processors

Transmitted
• Protocol - a set of
conventions governing the
exchange of data between
hardware and/or software
components in a
communications network

7.5 Networks
•Benefits of networks -

• Sharing of peripheral devices

• Sharing of programs and data

• Better communications

• Security of information

• Access to databases

Types of Networks
• Wide area network (WAN) - a communications network that covers
a wide geographical area, such as a country or the world

Metropolitan area network (MAN) - a
communications network covering a
city or a suburb
Local area network (LAN) - connects
computers and devices in a limited
geographical area

Types of Networks
•Host computer - a mainframe or midsize central
computer that controls the network
•Node - any device that is attached to a network
•Backbone - a high-speed network that connects
LANs and MANs to the internet
Client/server LAN -
Clients - microcomputers that
request data
Server - a powerful
microcomputer that supplies data
and manages shared devices

• Peer-to-peer LAN - all of LANs
Types
microcomputers on the
network communicate
directly with one another
without relying on a server
Components of LANs
-Connection or cabling
system
-Microcomputers with
network interface
cards
-Network OS
-Other shared devices
-Routers, bridges, and
gateways
-Hub

Topology of LANs
• Bus network – all nodes are
connected to a single wire
or cable, the bus, which has
two endpoints
• Each communication device
on the network transmits
electronic messages to
other devices.
Ring network - all
microcomputers and other
communications devices
are connected in a
continuous loop

Topology of LANs
• Star network - all microcomputers and other
communications devices are connected to a central
server

Intranets, Extranets, & Firewalls
•Intranet - an organization’s internal private network that uses the infrastructure
and standards of the internet and the web

•Extranets - private intranets that connect not only internal personnel but also
selected suppliers and other strategic parties

•Firewalls - a system of hardware and software that blocks unauthorized users
inside and outside the organization from entering the intranet

•Virtual private network – are private networks that use a public network (usually
the internet) to connect remote sites.

7.6 The Future of Communications
• Satellite-based systems - categorized into four types
• TV direct-broadcast system
• GPS system
• Satellite transmission to handle cellphone and
paging services
• Global high-speed low-orbital satellite networks
Beyond 3G to 4G
Photonics - optical technologies at warp speed
Utilities become communications companies
Software-defined radio
The grid

7.7 Cyberethics

• Controversial material
and censorship -

• Blocking software

• Browsers with ratings

• The V-Chip


Chapter 8
Files, Databases, & E-Commerce

8.1 Managing Files: Basic Concepts

• Data storage hierarchy - levels
of data stored in a computer:

• Bits
• Character (bytes)
• Fields
• Records
• Files
•

Key Field
• A key field uniquely identifies a record for processing and retrieval
• The primary characteristic of the key field is that it is unique

•Types of Files

•Program files - contain computer instructions
–Source program files
–Executable files
•Data files - files that contain data (words, numbers, pictures,
sounds, etc.)

Other Common Types of Files
•ASCII

•Image (graphic)

•Audio

•Animation/video

•Web

•Desktop publishing

•Drivers

•Windows operating systems

Two Types of Data Files
• Transaction file -
• Master file -
• a temporary holding file that
• a data file containing relatively
holds all changes to be made to
permanent records that are
the master file: additions,
generally updated periodically
deletions, and revisions

Data Access Methods

• Sequential storage - • Direct access storage -
• data is stored and • the computer can go
• etrieved in sequence • directly to the information
desired

Offline versus Online Storage

• Offline storage - • Online storage -
• data is not directly accessible for • stored data is randomly (directly)
processing until the tape or disk accessible for processing
it’s on has been loaded onto an
input device

8.2 Database Management Systems
•Database management system (DBMS) - programs that control the
structure of a database and access to the data
•Types of database access:
• Individual databases
• Multiuser databases

• Advantages of DBMS
• Reduced data redundancy
• Improved data integrity
• Increased security
• Ease of data maintenance

8.3 Database Models
• Hierarchical database - fields or records are arranged in related groups,
resembling a family tree, with child (lower-level) records subordinate to
parent (higher-level) records

Example of cruise ship reservation system

Database Models
• Network database - similar to a hierarchical database, but each child
record can have more than one parent record

Example of college class-scheduling system

Database Models
• Relational database - relates (connects) data in different files through
the use of a key field, or common data element

Example of state department of motor vehicles database

Database Models

•Object-oriented database - uses “objects”--software written in small,
reusable chunks--as elements within database files

•An object consists of:

• Data in any form, and
•
• Instructions on the actions to take on the data

8.4 Features of a Database Management System
•A database management system includes the following components:

lData Dictionary - procedures document or disk file that
stores the data definitions and descriptions of the
structure of data used in the database

lDBMS Utilities are programs that allow you to maintain
the database

lReport Generator is a program for producing an on-
screen or printed document from all or part of a
database.

Database Management System Components

•A database management system includes the following components
(continued):

lAccess Security - a feature allowing database
administrators to specify different access privileges
for different users of a DBMS

lSystem Recovery - enable the database
administrator to recover contents of the database
in the event of a hardware or software failure

8.5 Databases & the New Economy: E-Commerce, Data
Mining, & B2B Systems
• E-commerce (electronic commerce) - the buying and selling of
products and services through computer networks

No limits on the uses of e-commerce

Data Mining

•Data mining (DM) - the computer-assisted process of sifting through and
analyzing vast amounts of data in order to extract meaning and discover
new knowledge

•Data mining process consists of:
• Data acquisition
• Data cleansing
• Meta-data generation
• Data transport to data warehouse
• Searching for patterns
• Interpreting results

Business-to-Business (B2B) Systems

• B2B - a system in which a
business sells to other
businesses, using the Internet or
a private network to cut
transaction costs and increase
efficiencies

8.6 Ethics of Using Databases: Concerns about Accuracy
& Privacy

• Morphing - process in which a film or video is displayed on a computer
screen and altered pixel by pixel, or dot by dot, into something else

The Ethics of Using Databases
• Manipulation of sound can be used:
• Positively as in the music industry
• Negatively for misrepresentation

• Manipulation of video &
television Manipulation of photos

• Privacy - the right of people not to reveal information about
themselves

• The Ethics of Using Databases

• Accuracy and completeness – can be issue when searching
for historical data

• Monopolizing information – by an individual or organization
could lead to access related issues

Online privacy can be invaded by:

• Name migration
• Identity theft
• Resume rustling and online snooping
• Government prying and spying

Session 4
Chapter9 TheChallengesoftheDigitalAge
9.1SecurityIssues:ThreatstoComputers&CommunicationsSystems
9.2Security:SafeguardingComputers&Communications
9.3Quality-of-LifeIssues:TheEnvironment,MentalHealth,&theWorkplace
9.4EconomicIssues:Employment&theHaves/Have-Nots Technology,theJobKiller?
9.5TheDigitalEnvironment:IsThereaGrandDesign?

Chapter10 ThePromisesoftheDigitalAge
10.1EmergingGlobalTelecommunications
10.2ArtificialIntelligence
10.3Information&Education
10.4Health,Medicine,&Science
10.5Commerce&Money
10.6Entertainment&theArts
10.7Government&ElectronicDemocracy
10.8Jobs&Careers

Chapter11 InformationSystems
11.1Organizations,Managers,&Information
11.2Computer-BasedInformationSystems
11.3SystemsDevelopment-TheSixPhasesofSystemAnalysisandDesign


Chapter 9
The Challenges of the Digital Age

The Challenges of the Digital Age
Society & Information Technology Today
9.1 Security Issues: Threats to Computers &
Communications Systems

9.2 Security: Safeguarding Computers &
Communications

9.3 Quality-of-Life Issues: The Environment, Mental
Health, & the Workplace

9.4 Economic Issues: Employment & the Haves/Have-
Nots

9.5 The Digital Environment: Is There a Grand Design?

9.1 Security Issues: Threats to Computers &
Communications Systems
• Errors & Accidents:

• Human errors
• - humans can’t assess own information needs
• - human emotions affect performance
• - humans act on their perceptions
•
• Software errors

• Procedural errors
•
• Electromechanical problems

• “Dirty data” problems

Errors & Accidents
•Human errors

•Procedural errors – computer failures occur as a result of non-
compliance of procedures

•Software errors – software bugs

•Electromechanical problems – failure of mechanical systems due
to faulty construction,overheating, wearing out, or damage

•“Dirty data” problems - incomplete, outdated, or otherwise
inaccurate data
•

Natural & Other Hazards
• Natural hazards

• Civil strife and terrorism

Crimes Against Computers & Communications

• Theft of hardware - shoplifting an accessory
• Theft of software and data - illegal copying of programs
• Theft of time and services – using employer’s computer time to play
games
• Theft of information – stealing confidential personal records
• Crimes of malice and destruction – abusing or vandalizing computers

Crimes Using Computers & Communications

• Using information technology to assist in a crime

• Investment fraud

• Tools to detect fraud:

• Rule-based-detection software

• Predictive-statistical model software

Worms & Viruses

•Worm - a program that copies itself repeatedly into a computer’s memory or
onto a disk drive

•Virus - a “deviant” program, stored on a computer drive, that can cause
unexpected and often undesirable effects, such as destroying or corrupting
data

•Anti-virus software - scans a computer’s hard disk, floppy disks, and main
memory to detect viruses and destroy them

Computer Criminals

•Hackers - gain unauthorized access to computer or telecommunications
systems

•Crackers - illegally break into computers for malicious purposes

•Employees - more than 80% of all IT crime perpetrators

•Outside users - suppliers and clients

•Professional criminals - organized crime rings

9.2 Security: Safeguarding Computers &
Communications
• Security - system of safeguards for protecting information technology

• Identification & Access

• Encryption

• Protection of software and data

• Disaster-recovery plans

Identification & Access
• What you have - • Cards
• What you know • Keys
• Who you are • Signatures
• Badges
What you have PIN (personal
identification number) - the
What you know… security number known
only to you that is required
to access the system
Who you are Password - a special
word, code, or symbol
required to access a
computer system

Identification & Access

• What you have
• Biometrics - science of
measuring individual body
• What you know
characteristics

• Who you are…

Iris scan

Encryption

•Encryption - the process of altering readable data into unreadable form to
prevent authorized access

• Private key - same secret key used by both sender and receiver

• Public key - two keys are used

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