Introduction to Information Technology

Dosen: DarulQuthni

NIDN: 0128057803

Email: darulquthni@piksiinputserang.ac.id

Session 1Chapter 1 1.Introduction to Information Technology1.1 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 22.1 Choosing Your Internet Access Device & Physical Connection: The Quest for Broadband2.2 Choosing Your Internet Service Provider (ISP)2.3 How Does the Internet Work?2.4 Email Software & Carriers2.5 The World Wide Web2.6 The Online Gold Mine: More Internet Resources

Using Information Technology

Chapter 1Introduction 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 ComputersAll Computers, Great & Small: The Categories of Machines

1. Supercomputers

2. Mainframes

3. Workstations

4. Microcomputers

5. Microcontrollers

NEC Earth Simulator –the world’s fastest computer

All Computers, Great & Small: The Categories of Machines

l Supercomputers

1. Mainframes

2. Workstations

3. Microcomputers

4. Microcontrollers

IBM z900

All Computers, Great & Small: The Categories of Machines

1. Supercomputers

2. Mainframes

3. Workstations

4. Microcomputers

5. Microcontrollers

Workstation – Sun Ultra450

All Computers, Great & Small: The Categories of Machines

1. Supercomputers

2. Mainframes

3. Workstations

4. Microcomputers

5. Microcontrollers

HP Compaq Businessd220 tower

microcomputer

Compaq Evo desktop microcomputer

Laptop computerPersonal Digital Assistant

All Computers, Great & Small: The Categories of Machines

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 + Clients linked together form a

client/server network

SERVER

CLIENT

1.3 Understanding Your Computer: What If You Custom-Ordered Your Own PC?

How Computers Work - Concept #1The purpose of a computer is to process data into information.

• Data

The raw facts and figures that are processed into information

• Information

Data that has been summarized or otherwise manipulated for use in decision making

• Hardware

All the machinery and equipment in a computer system

• Software

All the instructions that tell the computer how to perform a task

How Computers Work - Concept #2Computers consist of hardware and software.

How Computers Work - Concept #3All computers follow the same five basic operations.

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Keyboard

Mouse

How Computers Work - Concept #3All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Processor chip

Motherboard

Case or system cabinet

How Computers Work - Concept #3All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

• Primary storage (memory) - RAM

• Computer circuitry that temporarily holds data waiting to be processed

• Secondary storage (storage) - ROM

•• The area in the computer where

data or information is held permanently

How Computers Work - Concept #3All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

CD Drive

How Computers Work - Concept #3All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

SpeakersMonitor

How Computers Work - Concept #3All computers follow the same four basic operations

1. Input

2. Processing

3. Storage

4. Output

5. Communications

Printer

How Computers Work - Concept #3All computers follow the same four basic operations

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 softwareEnables 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

Using Information Technology

Chapter 2The 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 & OtherThrough-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) - allows any user on a given email system to send a message and have it pop up instantly on the screen of anyone else logged onto that system

• Mailing Lists: Email-based discussion groups

• Listserv – is an automatic mailing-list server that sends email to subscribers participating in discussion topics

Netiquette: Appropriate Online Behavior

Consult FAQs

Avoid flaming

Do not SHOUT

Be careful with jokes

Avoid sloppiness

Do not send huge file attachments

Quote with relevant portion, when replying

Do not “overforward”

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 websiteA 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 featuresHistory list - allows you to return to a page you have recently visitedBookmarks 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 arrowsFrames 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 SearchingChoose search items well with the correct spellingUse phrases with quotation marks Put unique words first in a phraseUse operatorsUse wildcards Read the Help or Search Tips sectionTry 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 & VideophoneInternet telephony - using the Net to make phone calls, either one-to-one or for audio conferencingVOIP 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.

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Pendidikan Transportasi

Authentication and Authorization

Hierarchical Storage Management

Application ServerWeb Server

Operating System RelationalDBMS

Workflow Management

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ERP System

Considerations: Resiliency, Scalability, Flexibility, Modularity

E-mail

WebServer

Operating System

WebEditorWYSIWYG editors WYSIWYM editors

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

WebHostingcPanel, 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 computersMore Internet ResourcesNewsgroups – for online typed discussions on specific topicsReal-time chat – typed discussions among online participantsTelnet: 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

• E-commerce• Auctions – linking individual buyers and sellers• Online finance – trading, banking, and e-money• Online job hunting• B2B commerce

Trade and Commerce

Session 2Chapter 3 Application Software3.1 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 Software4.1 The Components of System Software4.2 The Operating System: What It Does4.3 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

Using Information Technology

Chapter 3Application 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•Worksheet files; xls, xlsx,•Database files; mdb, dbf

Exchanging files between programs:•Importing•Exporting

List File Format Extension

List File Useful Software

Types of Application Software

Examples:

• Word processing programs• Spreadsheets• Database managers

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

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

Desktop, Icons & Menus

Desktop, Icons & MenusMenu - a list of options to choose from--a list of commands for manipulating dataPull-down menu - a list of options that pulls down from the menu bar at the top of the screenCascading menus - menus that seem to fly back to the left or explode out to the right

Pull-down menuPull-down menu

Desktop, Icons & Menus

• 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

• 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

Documents, Toolbars, & Windows

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 commandsScrolling - 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

• 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

Editing Documents

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:• Single-spaced• Double-spaced• One-column• Two columns• Several columns

Margins and justification:• Left margin• Right margin• Top margin• Bottom margin• Justification• Left-justification• Centering

Formatting Documents

Headers, footers, and page numbers:

• Header• Footer• Page numbers

Other formatting:• Borders• Shading• Tables• Footnotes• Graphics• Clip art

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

Printing, Faxing, or Emailing Documents

Saving Documents

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

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

• Comments or questions can be inserted into the documents

Tracking Changes & Inserting Comments

3.4 SpreadsheetsThe 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

The Basics: How Spreadsheets Work

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

The Basics: How Spreadsheets Work

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 dataBenefits 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:• Key field - a field that is

used to sort data• Primary key - holds a

unique value for each record• Foreign key - used to cross-

reference data among relational tables

Finding what you want:

• Querying - locating and

displaying records

Sorting and analyzing records and applying formulas:

• Sorting data - alphabetically, numerically, geographically, or in some other order

Putting search results to use:

• Saving• Formatting• Printing• Copying• Transmitting

The Basics: How Databases Work

Personal Information ManagersPersonal information can include any of the following:•Personal notes/journal•Address books•Lists (including task lists)•Significant calendar dates

• Birthdays• Anniversaries• Appointments and meeting

•Reminders•Email, instant message archives•Fax communications, voicemail•Project management features•RSS/Atom feeds•Alerts•References (including scientific references, websites of interest)

Free and open-source collaborative software

Client-ServerBongo · Buni Meldware · Citadel · DAViCal · Kolab · OpenGroupware.org · Open-Xchange · Scalix · Zimbra · Zarafa

Web based

Citadel · eGroupWare · Group-Office · Horde · KnowledgeTree · Kolab · Feng Office Community Edition · phpGroupWare · ProjectPier · Simple Groupware · Tine 2.0

Personal information managers

Evolution · Kontact · Spicebird · Mozilla Sunbird · Mozilla Thunderbird/Lightning

3.6 Specialty Software

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

• 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

Presentation Graphics Software

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 - graphics program that allows users to simulate painting on screen

Vector image

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 -

Using Information Technology

Chapter 4System 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

The Operating System: What It DoesCPU 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

The Operating System: What It DoesFile 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

The Operating System: What It DoesTask Management

Number of Users

Number of Processors

Order of Processing

Multi-tasking One One Concurrently

Multi-programming

Multiple One Concurrently

Time sharing Multiple One Round robin

Multi-processing

One or more Two or more

Simultaneously

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

Utilities: Service Programs

• 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

Utilities: Service Programs

• Disk scanner and disk cleanup utilities:

• Detect & remove unnecessary files

• Detect & correct disk problems

4.4 Common Operating Systems

Desktop & Laptop Operating Systems

• Platform - a particular processor model and operating system on which a computer system is based

• Disk Operating System (DOS) - the original operating system produced by Microsoft, which had a hard-to-use command-driven user interface

Operating system

General History · Timeline · List · Comparison · Usage share · Development · Advocacy

KernelArchitecturesGeneral Monolithic kernel · MicrokernelSubtypes Exokernel · Nanokernel · HybridComponents User/Kernel space · Server · Loadable kernel module · Device driver

Process management

Concepts Process · Process control block · Interrupt · Thread · Context switch · Scheduling

CPU modes Protected mode · Supervisor mode

Scheduling algorithm

Cooperative multitasking · Preemptive multitasking · Round-robin scheduling · Fixed priority pre-emptive scheduling · Multilevel feedback queue · Shortest job next

Memory management

Memory protection · Segmentation · Paging · Segmentation fault · General protection fault · Bus error

Examples AmigaOS · BeOS · BSD · DOS · GNU · Linux · Mac OS · MorphOS · OS/2 · ReactOS · Solaris · Unix · Windows · more...

Miscellaneous concepts

Boot loader · Live CD · Live USB · PXE · API · Virtual file system · 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

•Windows NT - Microsoft’s multitasking OS which allows multiple users to share resources such as data and programs

•Windows 2000 - successor to Windows NT

•Novell’s Netware - a popular network operating system for coordinating microcomputer-based local area networks (LANs)

Network Operating Systems

• 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.

Network Operating Systems

•UNIX - a multitasking operating system for multiple users with built-in networking capability and versions that can run on all kinds of computers

• Sun Microsystems’ Solaris

• Berkeley Software Distribution (BSD)

AIX, HP-UX, IRIX, Linux, Minix, Ultrix, Xenix.

Network Operating Systems• Linux - a free version of UNIX, with continual improvements

resulting from the efforts of tens of thousands of volunteer programmers

Network Operating Systems

• 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

Using Information Technology

Chapter 5Hardware: The CPU

5.1 Microchips, Miniaturization, & Mobility

• 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

From Vacuum Tubes to Transistors to Microchips

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 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

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 & Boards• Bay - a shelf or

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 Microprocessor Chip

Two principal architectures or designs of microprocessors:

1 CISC (Complex Instruction Set Computing) - Supports a large number of instructions at relatively low processing speeds

2 RISC (Reduced Instruction Set Computing) - Used mostly in workstations, a great many seldom-used instructions are eliminated.

CPU TECHNOLOGIES

Architecture

ISA : CISC · EDGE · EPIC · MISC · OISC · RISC · VLIW · NISC · ZISC · Harvard architecture · von Neumann architecture · 4-bit · 8-bit · 12-bit · 16-bit · 18-bit · 24-bit · 31-bit · 32-bit · 36-bit · 48-bit · 64-bit · 128-bit · Comparison of CPU architectures

Parallelism

PipelineInstruction pipelining · In-order & out-of-order execution · Register renaming · Speculative execution · Hazards

Level Bit · Instruction · Superscalar · Data · Task

ThreadsMultithreading · Simultaneous multithreading · Hyperthreading · Superthreading

Flynn's taxonomy

SISD · SIMD · MISD · MIMD

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

Micro-computers Workstations Mainframes

Super-computers

Megahertz &Gigahertz

X

MIPS X X

FLOPS X

Fractions of a second X X X X

Processing Speeds: From Megahertz to Picoseconds

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

How Memory Works: RAM, ROM, CMOS, & Flash

Types of memory chips:1 RAM – to temporarily store program

instructions and data2 ROM – to store fixed start-up instructions3 CMOS – to store flexible start-up

instructions4 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 port3.SCSI port4.USB port5.FireWire port6.6Dedicated port7.Infrared port

Ports & Cables1. Serial port 2. Parallel port -

transmits 8 bits simultaneously

3. SCSI port4. USB port5. FireWire port6. Dedicated port7. Infrared port

Ports & Cables1. Serial port 2. Parallel port3. SCSI port - allows data

to be transmitted in a “daisy chain” to up to 7 devices

4. USB port5. FireWire port6. Dedicated port7. Infrared port

Ports & Cables1. Serial port 2. Parallel port3. SCSI port 4. USB port - can

theoretically connect up to 127 peripheral devices daisy-chained to one general-purpose port

5. FireWire port6. Dedicated port7. Infrared port USB port and connector

Ports & Cables

1. Serial port 2. Parallel port3. SCSI port 4. USB port5. FireWire port – for camcorders, DVD

players, and TVs6. Dedicated port 7. Infrared port

Ports & Cables

1. Serial port 2. Parallel port3. SCSI port 4. USB port5. FireWire port6. Dedicated port -

special-purpose ports

7. Infrared port Dedicated ports: mouse port, modem port, and keyboard

port

Ports & Cables1. Serial port 2. Parallel port3. SCSI port 4. USB5. FireWire port6. 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

Expandability: Buses & Cards

•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

Expandability: Buses & Cards

•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

Using Information Technology

Chapter 5

Hardware: Storage

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

5.4 Introduction Memory

5.5 Secondary Storage

5.6 Future Developments in Storage

5.4 Introduction Memory

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

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

How Memory Works: RAM, ROM, 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

How Memory Works: RAM, ROM, CMOS, & Flash

• Types of memory chips:

1 RAM – to temporarily store program instructions and data

2 ROM – to store fixed start-up instructions3 CMOS – to store flexible start-up instructions4 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

5.5 Secondary Storage

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

Floppy Disks

Floppy-Disk Cartridges

• Zip disks – 100, 250, or 750 megabytes

• 3.5-inch floppy disks – 1.44 megabytes

Zipdisk

Floppydisk

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 a microcomputer’s cartridge drive

Bits on disk - dark stripes are 0 bits and bright stripes are 1

bits

Optical Disks: CDs & DVDs

• Optical disk - a removable disk on which data is written and read through the use of laser beams

Optical Disks: CDs & DVDs• CD-ROM - read

only. For pre-recorded text, graphics, and sound

• CD-R - for recording on once

• CD-RW - for rewriting many times

Optical Disks: CDs & DVDs

• 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)

• Tape cartridges - modules resembling audio cassettes that contain tape in rectangular, plastic housings

Magnetic tape

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 used with an optical-card reader Smart card

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 disksMolecular electronicsSolid State DiskSci-Fi Disk Future:

• Carbon Nanoballs• Molecular memory:• Bacteria• Quantum mechanics:

Session 3Chapter 6 Hardware: Input6.1 Input & Output6.2 Input Hardware6.3 Input Technology & Quality of Life: Health & Ergonomics6.4 Input & Output6.5 Output Hardware6.6 Mixed Output: Sound, Voice, and Video Chapter7 Networks&Communications7.1FromtheAnalogtotheDigitalAge7.2ThePracticalUsesofCommunications7.3CommunicationsMediaandTransferRates7.4TransmittingData-Behind-the-ScenesDetails7.5Networks7.6TheFutureofCommunications 7.7Cyberethics Chapter8 Files,Databases,&E-Commerce8.1ManagingFiles:BasicConcepts Datastoragehierarchy-levelsofdatastoredinacomputer:8.2DatabaseManagementSystems 8.3DatabaseModels 8.4FeaturesofaDatabaseManagementSystem 8.5Databases&theNewEconomy:E-Commerce,DataMining,&B2BSystems 8.6EthicsofUsingDatabases:ConcernsaboutAccuracy&Privacy

Using Information Technology

Chapter 6

Hardware: Input

Input hardware - devices that translate data into a form the

computer can process

6.1 Input & Output

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

Internet terminal:• Set-top box• PDA

Point-of-sale (POS) terminal

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

• The mouse and its variants:

•

• Mouse • Trackball • Pointing stick

Touchpad Pointing stick

Pointing Devices

• The mouse and its variants:

•

• Mouse • Trackball • Pointing stick • Touchpad

Touch pad

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 called a puck

Digitizing tablet

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

Scanning and Reading Devices

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.

Scanning and Reading Devices

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

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

• OMR

• OCR

Scanning and Reading Devices

Mark-recognition and character-recognition devices:

• MICR

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

• OCR

Scanning and Reading Devices

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

Scanning and Reading Devices• 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 cameraattached 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

A tollbooth with RFID readers

RFID tag in a car for paying toll

Human-Biology-Input devices• Biometrics - the

science of measuring individual body characteristics

Screen of face recognition system

Palm print recognition reader

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

Ergonomic keyboard

Ergonomics: Design with People in Mind

Using Information Technology

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 voice form

•Hardcopy - printed output

Hardcopy

Softcopy

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

Traditional Softcopy Output: Display Screens

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

Traditional Softcopy Output: Display ScreensFactors 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

Traditional Softcopy Output: Display Screens

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•Liquid crystal display (LCD)•A plasma display •Surface-conduction electron-emitter display (SED)•Digital Light Processing (DLP) •An organic light-emitting diode (OLED)

DLP SED OLED

LCD

CRTFlat Panel

PLASMA

Traditional Softcopy Output: Display Screens

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

Traditional Softcopy Output: Display Screens

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

•Active-matrix display

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

Traditional Softcopy Output: Display Screens

• 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

Traditional Hardcopy Output: Printers

•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

Traditional Hardcopy Output: Printers

• 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

Traditional Hardcopy Output: Printers

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

Traditional Hardcopy Output: Printers• Plotter - a specialized output device designed

to produce high-quality graphics in a variety of colors

Traditional Hardcopy Output: Printers

• 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

BIOMETRICBRAINWAVE 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

Using Information Technology

Chapter 7Networks & 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 CommunicationsVideoconferencing & 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 & GroupwareWorkgroup computing also called collaborative computing – teams of co-workers (often at different sites) use networks of microcomputers to share information and to cooperate on projectsMade possible by networks, microcomputers, & groupware

TelecommutingTelecommuting - 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 ChannelsFiber-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 transmission medium that sends data over long distances--between regions, states, or countries

Microwave radio - transmits voice & data through the atmosphere as super-high-frequency radio waves called 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 guide users Pagers - simple radio

receivers that receive data (but not voice messages) sent from a special radio transmitter

• 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 formBroadband wireless digital services (3G) - “always on” technology which can quickly transmit video, still pictures, and music

Cellphone tower

Long-Distance Wireless Communications

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

• 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

Factors Affecting Data Transmission

Serial Data Transmission

Factors Affecting How Data Is Transmitted

• Serial vs. parallel transmission

Parallel data transmission - bits are transmitted through separate lines simultaneously

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

Factors Affecting How Data Is 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

Factors Affecting How Data Is Transmitted

Transmission mode - asynchronous vs. synchronousAsynchronous 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

Factors Affecting How Data Is 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 routeMultiplexing - transmission of multiple signals over a single communications channel

MultiplexersConcentratorsFront-end processors

Factors Affecting How Data Is 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 suburbLocal 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 internetClient/server LAN -Clients - microcomputers that request dataServer - a powerful microcomputer that supplies data and manages shared devices

Types of LANs• Peer-to-peer LAN - all 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 networksBeyond 3G to 4GPhotonics - optical technologies at warp speedUtilities become communications companiesSoftware-defined radioThe grid

7.7 Cyberethics

• Controversial material and censorship -

• Blocking software

• Browsers with ratings

• The V-Chip

Using Information Technology

Chapter 8

Files, Databases, & E-Commerce

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

• Bits

• Character (bytes)

• Fields

• Records

• Files•

8.1 Managing Files: Basic Concepts

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

• Master file - • a data file containing relatively

permanent records that are generally updated periodically

• Transaction file - • a temporary holding file that

holds all changes to be made to the master file: additions, deletions, and revisions

Data Access Methods

• Sequential storage -• data is stored and • etrieved in sequence

• Direct access storage - • the computer can go• directly to the

information desired

Offline versus Online Storage

• Offline storage - • data is not directly accessible for

processing until the tape or disk it’s on has been loaded onto an input device

• Online storage -• stored data is randomly (directly)

accessible for processing

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

The Ethics of Using Databases

• 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

The Ethics of Using Databases

Online privacy can be invaded by:

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

Session 4Chapter9 TheChallengesoftheDigitalAge9.1SecurityIssues: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 ThePromisesoftheDigitalAge10.1EmergingGlobalTelecommunications 10.2ArtificialIntelligence10.3Information&Education 10.4Health,Medicine,&Science10.5Commerce&Money10.6Entertainment&theArts10.7Government&ElectronicDemocracy 10.8Jobs&Careers

Chapter11 InformationSystems11.1Organizations,Managers,&Information11.2Computer-BasedInformationSystems11.3SystemsDevelopment-TheSixPhasesofSystemAnalysisandDesign

Using Information Technology

Chapter 9

The Challenges of the Digital Age

The Challenges of the Digital Age Society & Information Technology Today

9.1Security Issues: Threats to Computers & Communications Systems

9.2Security: Safeguarding Computers & Communications

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

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

9.5The 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 - • What you know• Who you are

• Cards• Keys• Signatures• Badges

What you have

What you know…

Who you are

PIN (personal identification number) - the security number known only to you that is required to access the systemPassword - a special word, code, or symbol required to access a computer system

Identification & Access

• What you have

• What you know

• Who you are…

Iris scan

• Biometrics - science of measuring individual body characteristics

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

Protection of Software & Data•Control of access - restricts access to data files to those with a need to know•Audit controls – track which programs and servers were used, which files have been opened, etc.•People controls - check resumé facts, separate employee functions, shred papers, etc.

Disaster-Recovery Plan

Disaster-recovery plan - a method of restoring information-processing operations that have been halted by destruction or accident

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

•Environmental problems:

• Manufacturing by-products - exposing semiconductor industry workers to a variety of hazardous toxins• Disposal by-products• Disposal by-products - “e-waste” - obsolete or broken PCs, monitors, printers, cellphones, TVs and other electronics• Environmental blight• Environmental blight - visual pollution represented by wireless towers, roof antennas, satellite dishes, and all the utility poles topped with transformers and strung with electric, phone, cable-TV, and other wires•

Environmental problems:

•Manufacturing by-products

•Disposal by-products

•Environmental blight

•Possible risks of nanotechnology - manipulating materials such as carbon, zinc, and gold at molecular level

Mental-Health Problems

•Isolation - going for days without actually speaking with or touching another person

•Gambling - information technology makes it almost unavoidable

•Stress - 83% of corporate network administrators reported “abusive and violent behavior” by employees toward computers

Workplace Problems: Impediments to Productivity

•Misuse of technology - computers may be costing U.S. companies tens of billions of dollars a year in downtime, maintenance and training costs, game playing, and information overload

•Fussing with computers - all the fussing that employees do with hardware, software, and online connections

•Information overload - employees tend to work longer hours under more severe deadline pressure

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

• Technology, the Job Killer?

• Hundreds of companies are replacing service representatives with voice software.

• Gap between Rich & Poor

• Employees with technology skills earn roughly 10–15% higher pay

9.5 The Digital Environment: Is There a Grand Design?

•Internet2 - a cooperative university/business education and research project that enables high-end users to quickly and reliably move huge amounts of data over high-speed networks

•The 1996 Telecommunications Act - designed to let phone, cable, and TV businesses compete and combine more freely

The Digital Environment: Is There a Grand Design?

•ICANN – a private corporation that regulates the domain names that overlie IP addresses and identify the website type

•Whom Does the Internet Serve?

•In a World of Breakneck Change, Can You Still Thrive? upgrade your skills, specialize, and market yourself

Using Information Technology

Chapter 10

The Promises of the Digital Age

10.1 Emerging Global Telecommunications

•Two models of telecommunications:

•Tree-and-branch - a centralized information provider sends out messages through many channels to thousands of consumers

•Switched-network - people on the system are not only consumers of information (“content”) but also possible providers of it

The Potential Effect of the Switched-Network Model:Napster & the Rise of File Sharing

•The switched-network file-swapping model could well change the basic economics not only of the music business but also of the online book-publishing business.

10.2 Artificial Intelligence

•Artificial intelligence - a group of related technologies used for developing machines to emulate human qualities

•Natural language processing• Natural language processing - the study of ways for computers to recognize and understand human language•Expert systems•Intelligent agents•Pattern recognition•Fuzzy logic•Virtual reality and simulation devices•Robotics

Expert SystemsExpert system - an interactive computer program used in solving problems that would otherwise require the assistance of a human expertKnowledge baseInference engineUser inference

Intelligent AgentsIntelligent agent - a form of smart software, or software with built-in intelligence that monitors work patterns, asks questions, and performs work

Pattern Recognition

•Pattern recognition - involves a camera and software that identify recurring patterns in what they are seeing and recognize the connections between the perceived patterns and similar patterns stored in a database

Fuzzy LogicFuzzy logic - a method of dealing with imprecise data and uncertainty, with problems that have many answers rather than one

Virtual Reality & Simulation devices

• Virtual reality (VR) - a computer-generated artificial reality which projects a person into a sensation of three-dimensional space

A virtual reality rendering of Rome

Robotics• Robotics - the development and study of machines that can perform work normally done by

people

• Robot - an automatic device that performs functions ordinarily executed by human beings or that operates with what appears to be almost human intelligence

Two Approaches to Artificial Intelligence: Weak versus Strong AI

•Weak AI - claims that computers can be programmed to simulate human cognition

•Strong AI - claims that computers can be made to think on a level that is at least equal to humans and possibly even be conscious of themselves

•Neural networks, genetic algorithms, and cyborgs are three examples of strong AI.

Artificial Life, the Turing Test, & AI Ethics

•Artificial life or A-life - the field of study concerned with “creatures” that are created, replicate, evolve, and die as if they were living organisms

•Turing test - intended to determine whether a computer possesses intelligence or awareness

•Here a human judge converses by means of a computer terminal with two entities hidden in another location

Turing Test

10.3 Information & Education• When used by trained teachers in middle schools computers can

significantly enhance performance in math learning.

• Students exposed to the internet in high school say they think the web has helped them improve the quality of their academic research and of their written work.

• One revolution in education—before, during, and after the college years— is the advent of distance learning, or “cyberclasses,” along with the explosion of internet resources.

10.4 Health, Medicine, & Science

Operating room output

Health & Medicine

•Computer technology is also radically changing the tools of medicine.

•Besides physicians, patients and health consumers are also going online.

Help for Stephen Hawking

Science

•Scientists have long been users of information technology.

•Collaboratory - an internet-based collaborative laboratory, in which researchers all over the world can work easily together even at a distance

An entomologist in Central America

10.5 Commerce & Money

•Sales & Marketing – sales representativesmust be comfortable with computertechnology.

•Retailing Becomes E-Tailing – thechallenges for internet food ventures are daunting.

•Banking & E-money - the world of cybercash has come to banking.

•Stock Trading - online trading has changed the nature of trading institutions themselves.

•Manufacturing - the ultimate goal of factory-automation experts is the lights-out factory.

10.6 Entertainment & the Arts

•Information technology is being used for all kinds of entertainment, ranging from video games to telegambling. It is also being used in the arts, from painting to photography.

10.6 Entertainment & the Arts

•Information technology is being used for all kinds of entertainment, ranging from video games to telegambling. It is also being used in the arts, from painting to photography.

Computer drivenindoor year-round skiing

Music•The World Wide Web is standing the system of music recording and distribution on its head—and, in the process, is changing the financial

underpinnings of the music industry.

MoviesComputer techniques have even been used to develop digitally created actors—called “synthespians.”

Animation is not the only area in which computers are revolutionizing movies. Digital editing has radically transformed the way films are assembled.

10.7 Government & Electronic Democracy• Communication between

residents & local government

• Online voting

• Campaigning

• Paying taxes & fines

Touch screen voting

10.8 Jobs & Careers

• Ways for you to find employers

• Ways for employers to find you

• What do you want to do?

Using Information Technology

Chapter 11

Information Systems

11.1 Organizations, Managers, & Information•The flow of information within an organization -

• Horizontally - reflects functional areas

• Vertically - reflects management levels

Departments

• Research and development (R&D)

• Production (operations)

• Marketing and sales

• Accounting and finance

• Human resources (personnel)

• Information systems (IS)

Management Levels

•Top (or senior) managers - concerned with long-range, or strategic, planning and decisions

•Middle-level managers - make tactical decisions to implement the strategic goals of the organization

•Lower (supervisory) managers - make operational decisions - predictable decisions that can be made by following well-defined sets of routine procedures

Types of Information

•Structured information - detailed, current, not subjective, concerned with past events, records a narrow range of facts, and covers an organization’s internal activities

•Unstructured information - summarized, less current, highly subjective, concerned with future events, records a broad range of facts, and covers activities outside as well as inside an organization

•Semi-structured information - some structured information and some unstructured information

An organization chart and management

levels and responsibilities

11.2 Computer-Based Information Systems

• For lower managers - TPSs• For middle managers -

MISs and DSSs• For top managers - ESSs• For all levels, including

nonmanagement – OASs, ESs, and Cooperative work systems

Transaction Processing System (TPS)

•TPS - a computer-based information system that keeps track of the transactions needed to conduct business

•Features include -

• For lower managers• Produces detail reports• One TPS for each department• Forms the basis for MIS and DSS

Management Information System (MIS)

•MIS - a computer-based information system that uses data recorded by TPS as input into programs that produce routine reports as output

•Features include -

• For middle managers• Draws from all departments• Produces several kinds of reports

Decision Support System (DSS)

• DSS - a computer-based information system that provides a flexible tool for analysis and helps managers focus on the future

• Features include -

• For middle managers• Produces analytic models

Geographic DSS for earthquake insurance

Executive Support System (ESS)• ESS - an easy-to-use DSS made especially for top managers;

it specifically supports strategic decision making

Components of an ESS

Office Automation System (OAS)• OAS - combine various technologies to reduce the manual labor

required in operating an efficient office and to increase productivity

Office automation systems

Expert System (ES) and Cooperative systems

•ES – is a set of interactive computer programs that help users solve problems that would otherwise require the assistance of a human expert

•Cooperative systems – organizations that have networks that use groupware to enable cooperative work by groups of people

11.3 Systems Development - The Six Phases of System Analysis and Design

•System - a collection of related components that interact to perform a task in order to accomplish a goal

•Participants in a project involving a new system or changes to an existing one -•

Users • Management • Technical staff

The Six Phases of Systems Analysis & Design

SDLC

The First Phase - Conduct a Preliminary Investigation• Objectives -

1. Conduct the preliminary analysis

2. Propose alternative solutions

3. Describe the cost & benefits

4. Submit a preliminary plan

The Second Phase - Do an Analysis of the System• Objectives -

1. Gather data2. Analyze the data3. Write a report

Data flow diagram

The Third Phase - Design the System• Objectives -

1. Do a preliminary design

2. Do a detail design3. Write a report

The Fourth Phase - Develop the system• Objectives -

1. Develop or acquire the software

2. Acquire hardware3. Test the system

The Fifth Phase - Implement the System

• Objectives -

1. Convert to the new system

2. Train the users

The Sixth Phase - Maintain the System• Objective -

• To adjust and improve the system by having system audits and periodic evaluations and by making changes based on new conditions