Mainframe High volume processing, financial transactions

Supercomputer High volume, very high processing used for research and defense

Minicomputer Midsize computer used at universities, schools, and corporations

Workstation Microprocessor computer equal in power to minicomputers

Personal computer Desktop computer less powerful than a workstation

Dumb terminals Accesses programs and data over a network but has no processing capabilities of its own

Network computer Accesses programs and data over a network and has the capability to process on its own

Laptop computers Portable, lightweight personal computers

Personal digital assistants A pocket-size computer for storing personal information and not quite as powerful as a personal computer

Types of Computers

Business

Vertical

Custom/Individual

CAD/CAM

Bulletin

Productivity

Spreadsheets

Word processors

Desktop publishers

Graphics

Electronic mail

Scheduling/Project planning

Software suites

Personal digital assistant software

Types of Software Applications

New Learning Technologies

Internet

Multimedia

Virtual reality

Distance learning

Data warehousing

Shift in information infrastructure

1970’s-1980’s 1990’s-?

Infrastructure focused on data crunching and

data storage

Infrastructure focused on communications,

connectivity, and service

The Information Age Timeline

Agrarian Economy

2000 + Years

1760’s

Industrial Economy

190 Years

Information Economy

75 Years +

1860’s 1960’s 2060’s

Today

Advances in society:• Irrigation• Forging• Concrete• Democracy• Architecture • Economics

Advances in Society:• Early cybernetics• Computerization• Miniaturization• Telecommunications• Space flight• Genetics

Advances in society:• Mass production• Steam engines• Railroads• Steel• Highways• Automobiles

Timeline of Agrarian to Informational Society

Progress of Technology through Time

ENIAC

==

Current TechnologyComposed of 17,000 vacuum tubes, 70,000 resistors, and

10,000 capacitors, the ENIAC (Electronic Numerical Integrator and Computer) weighed over 30 tons and took up

1800 square feet of floor space. Completed in 1945, the ENIAC was used for ballistics work and later on for weather

prediction.

Today’s technology uses vast numbers of electronic components in the form of miniaturized

integrated circuits contained on silicon chips. Modern day desk calculators exceed ENIAC’s

computational power and speed by far.

Abacus

Napier’s bones

Pascal’s mechanical calculator

Leibniz wheelJacquard

loom

Difference Engine

Analytical Engine

2000+ years ago to about 1600

16th and 17th centuries

1810 1830 1850

Augusta Ada first programmer

Mechanical Computers

1890 1924 1930

Hollerith creates Automatic Card Reader for U.S.

census

First electronic binary computers

Z1 and Z2IBM

founded

Early Electric Computers

1940

Enigma

1941

Colossus first digital computer

1946

Mauchly and Eckert complete

the ENIAC, a vacuum tube

digital computer

1947

Wartime Computers

1943

U.S. team builds Mark I computer, 8 feet tall and 50 feet long

Transistor developed

1950

IBM 650 created; IBM also ships the

first electronic computer, the

mainframe 701

Electronic and Digital Computers

Integrated circuit created

1958

Remington Rand builds UNIVAC 1

first stored memory

19571953

Minicomputers marketed by Digital

Equipment Corporation; Fortran

programming language created

1960

AT&T creates first commercial

modem

Miniaturization, Automation, and the Space Age

Intel micro-processor; first micro-computer

19711964 1969

Apollo 11 lands on the moon, guided by the

Apollo guidance computer

1970

SRI builds the first moving robot with artificial

intelligence

1965

PDP-8 becomes the first

successful mini-computer

IBM creates the System/360

series of computers; first supercomputer

is developed

1960

PDP-1, first digital mini-

computer with video display; first industrial

robot put to use by GM

Apple computer created

1976

IBM first micro- computer

1981

Macintosh computer created

1984 1994

Multimedia computers

and personal data

assistants developed

Personal and Multimedia Computers

1980 1986 1988 1990

DOS becomes the

industry standard

Microsoft releases

Windows 3.0

IBM introduces first laptop computer

IBM and Microsoft release the

OS/2 operating

system

Input Devices•Keyboard•Mouse•Trackball•Stylus

Central Processing Unit (CPU)•Microprocessor •Storage Devices (Hard Drives & Floppy Drives)

Output Devices•Monitor•Printer

Components of a Personal Computer System

Laptop Computer

Workstation

Supercomputer

Palmtop Computer

Personal Data Assistant

Types of Computers

Components of a VGA Monitor

Electron GunsThree electron guns locatedat the back of the monitor’s cathode-ray tube send out three electron beamsfor each of the primary colors.

Magnetic Deflection YokeThis mechanism uses electromagneticfields to bend the paths of the electronstreams.

Shadow MaskThe beams pass through holes in a metal plate called a shadow mask. The mask keeps the electron beams precisely aligned, so that colors are accurate. The monitor’s dot pitch is a measure of how closely the holes are spaced apart.

Phosphor CoatingThe phosphor coating is a material that glows when struck by an electronbeam. The screen is made up of triads of red, green, and blue phosphor dots. As the energy in the electron beam increases, the phosphor dots glow brighter. To create different colors, the intensity of each of the three beams is varied.

Computer Memory

SIMMSingle Inline Memory Modules are the most popular memory module of present day computers. The small circuit board contains three to nine DIP chips. SIMMs range in sizefrom 4MB to 32MB of memory.

DIPDual Inline Pin memory modules were onceused for main memory in older computer systems. Now they are used as componentson SIMM chips and are also used in cacheRAM.

ROMA Read Only Memory storage device hasinstructions permanently embedded in its circuits. ROM chips contain programs thatstart the computer and perform systemdiagnostics.

Virtual MemoryWhen a computer runs out of real memory (storing information in RAM), it employsa software technique to generate virtual memory, storing and swapping information on the computer’s hard drive.

Hard Disk Storage

Sealed Metal HousingThe housing protects the internal components from dust particles that couldblock the gap between the read/write headsand the platters, causing the hard drive tocrash.

Drive SpindleThe drive spindle is connected to a motor which spins one or more magnetically coated platters at several thousand revolutions per minute. More platters mean greater disk storage capacity.

Head ActuatorThis component moves the collection of read/write heads across the surface of the platters with extreme accuracy. It aligns the heads with the tracks thatlie in concentric circles on the platters.

Read/Write HeadThese read/write heads move in unison across the surfaces of the platters. The heads write data to the platters by aligning magnetic particles on the surface and read data by detecting the polarity of the particles.

SectorWhen formatting the hard drive, thecomputer divides the disk into radialsections called sectors.

TrackCircular and concentric pathsthe read/write heads follow when reading information from the disk.

How a Mechanical Mouse Works

As the ball rotates it turns the two rollers mounted perpendicular to oneanother. One roller corresponds to vertical movements of the mouse,another corresponds to horizontal movements.

Two small switches in the front of themouse register left and right mouseclicks.

A perforated wheel and a photoelectric switchmeasure the rotations the ball makes as the mouse is moved, thus moving the cursor on thescreen. The photoelectric switch consists of alight-emitting diode (emitter) on one side,and a phototransistor (receiver) on theother side. The perforated wheel is sandwiched between the two,turning the switch off and onas it rotates.

A third roller is usednot for measurement, but instead to keep the ball in place as the user moves the mouse.

Major Components of a Motherboard

SIMM RAM BankSingle Inline Memory Module stores data to be used by the microprocessor.

ROM BIOSBasic Input/Output Systemstores permanent instructionsthat start the computer.

Power ConnectorSupplies power to themotherboard.

16 Bit ISA SlotsAllows expansion of computer through modem, sound and video cards.

32 Bit PCI SlotsAllows expansion cards thatcan transfer data faster thanISA slots. Battery

Provides power for the system clock.

Cache RAMStores and retrieves informationfor the microprocessor at a faster rate than SIMM RAM so instructions can be executed faster.

MicroprocessorSingle integrated circuit that executes the majority of the instructionsto processdata.

External ModemPlugs into computer externally

Internal Modem

Fits inside computer

Modems can send data from one computer to another using telephone lines.

Modems are used in almost every aspect of work. Businesses use them to transfer files, data, and money. They are also used for teleconferencing, which allows people in various locations to communicate over vast distances; these are sometimes called virtual meetings. Schools use them to provide access to the Internet.

Modems and Their Uses

Computer Operating Systems: PC

Personal Computer

Command line interface:

DOS Mode

Graphical Interface:

Windows 95 or 98

DOS uses command lines to execute commands and to run programs.

Windows uses a graphical interface utilizing buttons, icons and pull down menus.

DOS Commands

Change to different drive

Make directory

Change directory

Delete directory

Change directory

Common DOS Commands

Command Purpose

dir directory list

cd (directory name) change directory

cd.. back up one directory

c: (d:, e:, etc.) change drive

md (directory name) make directory

del (file name) delete file

edit (file name) edit file

ren (file name) rename file

format (drive letter) format disk in drive

copy (file name) copy file

Computer Operating Systems: Macintosh

Macintosh computers use a graphical interface exclusively. It was the first home computer to use a graphical interface.

Computer Operating Systems: Macintosh

Macintosh pull-down menu bar

Clock and Find functions

File and drive icons

Trash icon used to delete files

Multitasking

One of the most important features of computer operating systems of today is multitasking. Multitasking is the ability to run two or more programs is simultaneously.

Adobe PhotoShopMicrosoft Word

Microsoft PowerPoint

++ ++

Microsoft Office is one of the most popular software suites available for business, educational, and personal computer use.

Contains:• Word processor• Database program• Spreadsheet• Presentation software• Information management

Software suites are full- featured versions of several different programs packaged together.

Software Suites

Word processors are the most commonly used program on computers today.

Microsoft Word screen interface

Key features:• Text formatting• Text editing• Table creation• Spell check • Grammar check• Find and replace• Mail merge• MacrosExample of a table in Microsoft Word

Word Processors

Spreadsheets are commonly and widely used to keep track of, update, create, and calculate information easily and efficiently.

Common uses:

• Keep track of money and financial records• Record information on groups of objects or collections

Key features:• Grids• Number formatting• Formulas• Macros• Ranges• Charting

Standard interface for Microsoft Excel

Spreadsheets

Two forms within a database in Microsoft Access

Database software sorts, organizes, and manipulates large amounts of information.

Key Features:• Sort• Find• Query• Link• Create reports

Common uses:• Address books• Bank records

Databases are most commonly used by businesses, government agencies, hospitals, and colleges.

Databases

Microsoft PowerPoint software showing layout of one group of slides for a presentation

Microsoft PowerPoint software showing layout of one group of slides for a presentation

Presentation software showing construction of one slide

Presentation software showing construction of one slide

This software is used to create presentations combining text, numbers, graphics, sounds, and animation.

This software is used to create presentations combining text, numbers, graphics, sounds, and animation.

Key features:

• Media options• Transitions• QuickTime movies

Key features:

• Media options• Transitions• QuickTime movies

Presentation Software

Object Linking and Embedding (OLE)

Object linking : Object linking is used to automatically update a document any time a source object is changed or updated.

Source object Destination

Once a source object is changed, the destination object is changed. Changes to a document cannot be made at the destination.

Creates and updates

Object Linking and Embedding (OLE)

Object embedding : Object embedding is used to copy an object from a source document to a destination object.

Source Object Destination

The object can be edited at either the source or the destination.

Identical Object

All Folders Pane Contents PaneFolders Pane Files Pane

Windows Explorer Window for Windows 95 (left) and Windows 98 (right)

The document Faclog.txt is being copied

from C drive to A drive.

Copying a File in Windows Explorer

My Computer Window: Windows 95 (left) and Windows 98 (right)

Title Bar

Menu Bar

Formatting Toolbar

Standard Toolbar

Insertion Point

Status Bar

Horizontal Scroll Bar

Taskbar

End-of-document Marker

Office Assistant

Vertical Scroll Bar

Ruler

I-beam Pointer

Clear Document Screen

Key the document name in this text

box.

After keying the document name, click

the Save button.

Save As Dialog Box

Click this down-pointing triangle to display the

drop-down menu.

Click this option to change to the disk in

drive A.

Changing the Default Folder

Up Scroll Triangle

Scroll Box

Vertical Scroll Bar

Down Scroll Triangle

Previous

Select Browse Object

Next

Horizontal Scroll BarScroll Box

Scroll Bars

Serif Typefaces San Serif Typefaces

Bookman Old Style Arial

Garamond Futura

Goudy Old StyleHaettenschweiler

Baskerville Old Face Impact

Poster Bodoni Century Gothic

Times New Roman Tahoma

Serif and Sans Serif Typefaces

Choose a typeface in this list box. Use the scroll bar at the right

side of the box to view various

typefaces available.

Choose a type style in this list box. The options in the box

may vary depending on the typeface

selected.

Choose a type size in this list box; or, select

the current measurement in the top box and then key

the desired measurement.

Font Dialog Box

Choose an animation effect

from this list.

The animation effect chosen

above is reflected in this preview box.

Font Dialog Box with Text Effects Tab Selected

Document with Nonprinting Symbols Displayed

Left Indent Marker

Alignment Button

Hanging Indent Marker

First Line Indent Marker

Right Indent Marker

Ruler and Indent Markers

Remove the check mark from this option to

turn off automatic numbering.

AutoCorrect Dialog Box with AutoFormat As You Type Tab Selected

Click a numbering option to select it and

then click OK or double-click the desired

option.

Click a bulleting option to select it and then

click OK or double-click the desired option.

Bullets and Numbering Dialog Box with Each Tab Selected

Key a tab measurement in this

text box.

Choose a tab alignment with options in this

section.

Choose a leader symbol with options in

this section.

Tabs Dialog Box

Columns Dialog Box

Current folder

Folder icon

Document icon

Open Dialog Box

Back

Up One Level

Search the Web

Delete

Create New Folder

Views Tools

Open Dialog Box Toolbar Buttons

Arranged Documents

Print Dialog Box

Make sure the correct printer name displays

here.

Specify the amount of text

to print with options in the Page range

section.

Click this Down-pointing triangle

to display a list of installed printers.

Click this button to set options for

the selected printer such as

paper size, layout,

orientation, paper source, and

paper quality.

Print multiple copies of a

document by increasing this

number.

Header Pane and Header and Footer Toolbar

Insert AutoText Insert AutoText into header/footer.

Insert Page Number Insert page number in header/footer.

Insert Number of Pages Prints the total number of pages in the active document.

Format Page Number Format the page numbers in the current section.

Insert Date Insert date in header/footer.

Insert Time Insert time in header/footer.

Page Setup Display Page Setup dialog box.

Show/Hide Document Text Turn on/off the display of document text.

Same as Previous Link/Unlink header/footer to or from previous section.

Switch Between Header Switch between the header pane and the footer and Footer pane.

Show Previous Show previous section’s header/footer.

Show Next Show next section’s header/footer.

Close Header and Footer Close header/footer pane.

Click this button Named To do this

Header and Footer Toolbar Buttons

Expanded Find and Replace Dialog Box

Table Move Handle

Gridline End-of-cell Marker

End-of-row Marker

Word Table

Cell Designations

Status Indicator

Title Bar

Menu Bar

Toolbar

Address Bar

Document Window

Status Bar

Scroll Bar

Internet Explorer Window

Design Mode

Microsoft Script Editor

Checkbox

Dropdown Box

Textbox

Submit

Reset

Password

Sound

Properties

Option Button

List Box

Text Area

Submit with Image

Hidden

Movie

Scrolling Text

Web Tools Toolbar Buttons

Elevation Buttons

Rotation Buttons

3-D View Dialog Box

Specify target

browser in this section.

Click here to view completed pages in browser when the conversion is

completed.

Click here to open Web

Options dialog box.

Click Publish to begin conversion.

Publish as Web Page Dialog Box

Start an online meeting by

clicking Call.

Volume Controls

Meeting participants will be listed in this window.

Microsoft NetMeeting Application Window

Word’s menus and toolbars are active.

Double-click embedded

Word object to edit it. Word’s

ruler bars become active.

Editing a Word Table Embedded in PowerPoint

Three-Dimensional Models

3-D models are used in many industries for creating objects, places, or experiences, which would not be possible under realistic conditions. 3-D models are used in film, television, architecture, engineering, medicine, law, and for many other purposes.

Graphics File Formats

Graphics, drawing, and painting programs use special file formats recognizable only to those programs. The main file formats have extensions such as gif, jpeg, bmp, tif and eps.

gif Graphics Interchange Format - used for uploading documents to online services and for passing documents between other types of computers. GIF is a compressed format that is designed to minimize file transfer time over phone lines.

jpeg Joint Photographic Experts Group - compresses and economizes the way in which data is stored, and identifies and discards extra data not essential to the display of the images.

tif Tagged-Image File Format - used to exchange documents between applications and computer platforms.

bmp Bitmap file format - the standard MS-Windows™ raster format.

eps Encapsulated PostScript file format - used by illustration and page layout programs

There are two main types of computer graphics images: vector images and raster images.

Vector graphics are made up of mathematically defined lines and curves called vectors.

Raster images consist of a grid, or raster, of small squares, known as pixels.

3-D Rendering, Animation, and Modeling Programs

This is an example of a 3-D modeling and animation program called Lightwave. These programs are used when it is not possible to experience live action or real-life situations and objects.

Image Editing SoftwareImage editing software is used to enhance pictures and photographs. Photographic manipulation and retouching is a common use of these programs.

This is an example of an image editing software program called Adobe PhotoShop. A picture can either be manipulated by a drawing or illustration program or be scanned in from a photograph or drawing.

CAD SoftwareCAD Software is used to create detailed drawings and engineering schematics for objects which can be manufactured or mass produced.

Some CAD programs allow the schematics to be sent directly to machines to be computer built and manufactured, which costs much less than having an engineer or manufacturer construct them by hand.

Most software of this type allows the drawings to be printed on a plotter, which is much faster than drafting by hand. These can then be made into blueprints.

Drawing, Painting, and Illustration Software

Here is an example of a paint program called CorelDraw.

Most of these programs use a mouse or a graphics tablet as an input drawing device.

Drawing, painting, and illustration programs are used to create digital pictures and are used in almost every industry.

Vector graphics are made up of mathematically defined lines and curves called vectors.

Vector and Raster Graphics

Raster images consist of a grid, or raster, of small squares, known as pixels.

This is an example of a vector-drawn line graphic.

Vectors

These squares are pixels.

Page Layout SoftwarePage layout or desktop publishing software is used to create printed media for books, catalogs, magazines, advertisements, and other printed materials.

An example of Quark Express, a layout software package commonly used in the print industry.

Wireless communication is used to send signals through the air. Electromagnetic signals are used to send encoded data such as infrared light, radio waves, and microwaves.

•Can be local, terrestrial, or satellite based.

•Remote controlled, local network transmissions, and satellite communication.

Wireless Communication

Uses and Types of Networks: LANs

Local Area Networks or LANs

LANs link computers and users in a more defined area, such as an office, a building, or adjacent buildings.

Computers in a LAN usually share one or more printers and storage devices.

A LAN can be connected to another LAN by use of a bridge.

A LAN can be connected to a dissimilar network type by using a gateway.

A LAN can also be connected to a wide area network (WAN) by using a router.

Network hard drives

Network printer

Local printer

Computer

Computer

Computer

Computer

Computer

Computer

A network is created when data communication channels link more than one computer or device. These connections can be permanent or temporary. Networks allow communication over short and vast distances and also allow users to share data. There are two basic types: local area networks and wide area networks.

Uses and Types of Networks: WANsWide Area Networks or WANs

WANs link computers and users over a wide geographic area. Wide area networks are usually linked by high-speed telephone communication channels or by satellite and microwave relays.

Other network types:

Client-Server Networks

In a client-server network, one or more computers on the network function as file servers. These file servers store programs and data which are accessed by other computers on the network, called clients.

Peer-to-Peer Networks

In a peer-to-peer network every computer is both a client and a server. All computers on the network are able to access and provide data to all the computers.

Modem connection

PrinterCompute

r

Modem

Computer

Computer

Computer

Modem

A network in Los Angeles

A network in New York City

Network Layouts

Linear Bus Networks

In a linear bus network, a single path (bus) connects each node (computer). Using a transceiver on each node, data is allowed to be sent along the bus in both directions. Linear networks encounter problems when two or more nodes send data at the same time, which jams and blocks all transmissions. The network will go down if a node is broken from the connection.

Local area networks can be organized in different ways. The three most common topologies of networks are linear bus, star, and ring.

Computer

Computer

Computer

Computer

Printer Printer

Bus

Star Networks

In a star network, each node is connected by its own path to the central hub. The hub acts as a switching station, routing data to the appropriate node. This topology prevents data jamming or collisions from occurring. This network can remain active even when a node is broken from the connection.

Computer

Computer

Computer

Computer

Computer

Printer

Host computer

Ring Networks

This network connects each node to every other node in a circular path. Messages and data travel around the circular path until reaching the destination. Ring networks prevent data collisions. Ring networks will go down if a node connection is broken.

Computer

Computer

Computer

Computer Computer

Computer

ComputerPrinter

BandwidthsAll digital information transmitted and received by computers and networking components is encoded as binary numbers: ones and zeros. A single piece of information, either a one or a zero, is called a bit.

The number of bits that can be transferred in a given second over a channel is called a bandwidth.

A bandwidth is measured in bits per second.

• Kpbs - One thousand bits per second

• Mbps - One million bits per second

A baud rate is used for modem speeds. A baud rate is the number of times per second a signal changes.

• A 2400 baud modem will transmit 1 bit with each signal change.

• Baud modems with speeds over 2400 may transmit more than one bit with each signal change.

Coaxial CablesCoaxial cables are often used for VCR, cable TV connections, telephone networks, and some computer networks. Coaxial cables consist of a center copper wire, insulation sheathing, a conducting and shielding wire mesh that protects against interference, and a plastic outer sheathing.

• Baseband and broadband coaxial cables are the two main types of coaxial cable. Baseband transmits one digital channel at 10 to 80 Mbps. Broadband transmits multiple analog channels.

• Baseband coaxial cable is used in computer networks.

• Broadband coaxial cable is used in cable television transmissions.

Copper wire

Insulation sheathing

Wire mesh

Plastic sheathing

Twisted-pair CablesCommon medium for connecting computers. Consists of plastic-wrapped copper wires in a plastic casing. Used in telephone and specially designed twisted-pair networks.

• Potential bandwidth up to 6 Mbps.

• Good for Internet and modem data connections but impractical for real-time music and video.

• Limits bandwidths of telephone/modem connections because the digital signals must be translated to analog signals.

Plastic casing

Plastic wrapping

Copper wires

Fiber Optic CablesFiber optic cable is a string of glass used to transmit light or photons. It contains a very pure central glass filament surrounded by a refractive material called cladding. Digital pulses at one end of the cable are translated into light pulses by use of a laser. The light pulses travel down the cable by bouncing off the cladding. The other end of the cable has a photodetector which transforms the light back into electrical impulses.

• Capable of transmitting up to 1000 billion bps.

• No interference from electromagnetic fields.

• Very expensive to install.

• Used primarily in telephone lines.

The Internet

The Internet is a vast system of millions of computers worldwide, connected by communication lines throughout the world. It is also known as the Net. More than 120 million people use the Internet today.

Uses of the Internet and the World Wide Web

Business

Entertainment

Education

Uses of the Internet and the World Wide Web

Information

Shopping

Communication

The World Wide Web (WWW)

The World Wide Web contains information and communication based on hypertext documents. A hypertext document is a document that contains links. Links can be buttons, colored or underlined text, or pictures that send you to related information and documents.

LinksLinksThese links would take you to a page about the President and Vice President.

These links would take you to a page about the President and Vice President.

Web Browsers

A Web browser is a program that is used to look up information and URL addresses on the Internet. These are programs such as Netscape and Microsoft Internet Explorer.

Microsoft Internet Explorer

Netscape

URLs

A URL or Universal Resource Locator is an address for finding information on the web. It is similar to a telephone number or mailing address.

Example: http://www.nasa.gov

http:// Hypertext Transfer Protocol Protocol interpretation

www On the World Wide Web Format information

nasa National Aeronautics Name of organizationand Space Administration

gov Government site Domain of organization

Other sites may have edu, com, or org at the end of the URL. edu educational site

com commercial site

org nonprofit organization

Web Browser Button and Commands

This is an example of Netscape’s command bar.

E-MailE-mail or electronic mail is used to send messages to anyone, anywhere in the world.

Screen of an e-mail message

An address, much like a URL, finds a person’s “mail box” location.

Common uses:

• To say hello

• Business transactions• Business communications

• Interoffice messaging

• Sending resumes

HTML

HTML or hypertext markup language is the means by which documents are created. These documents can have text, sound, graphics, animation, and links to a vast database of information.

NBC’s Web page

NBC’s Web page HTML code

Online Services and Service ProvidersAn online service is a company that provides access to the Internet. A browser is often included in these services. They usually include extra features besides Internet access such as e-mail, channels (similar to television), shopping, reference materials, news, and entertainment. One of the most popular of these is America Online.

An Internet service provider is a company that provides Internet access. It usually offers a browser but not additional features.

Screen of America Online showing the different channel selections.

Connecting to Online Services through the Internet

Online service with client software:

Uses Telnet, gopher, and FTP.

Must establish a TCP/IP connection.

Special features and functions but does not access the Internet.

Online service:

Available only to people who subscribe to the service.

Online service with proprietary Web browser:

A built-in Web browser to access the Internet.

Online service accommodating any Web browser:

Allows you to use any Web browser.

Connecting to the Internet

Terminal Connection to a Mainframe

Mainframe

Serial Line Internet Protocol (SLIP)

ISDN Line

Router

Cable Modem

Online Service

Cable Modem Connection

Point to Point Protocol (PPP)

Search EnginesA search engine is a program that allows you to search specific topics. Search engines and guides are used to find information when a URL address is not known.

Yahoo, Excite, and WebCrawler are some

common search engines used on the Internet.

Linking Networks to the Internet

Modem

Internet ServiceProvider(ISP)

Mainframe

Router

Network Network

NetworkNetwork

Regional NetworkRegional Network

Router

Satellite Link

Router

Network Access

PointNetwork Access Point

Computer Workstation

•Artificial Intelligence - Computer brains that become self-teaching and self-thinking.

•Cloning - Duplication of cells and DNA to create an exact copy of an organic being.

•Cybernetics - The union of the organic and inorganic.

•Virtual reality - All-encompassing computerized microworlds for business and entertainment.

What does the Future Hold for Computers and Society?

Detecting Computer Viruses

What is a computer virus?A computer virus is a relatively small program that can vary in its destructiveness from being a minor nuisance, to a major disaster. Three common methods of access include:

1) Disk in drive A: with virus program2) Downloaded files through BBS/Internet3) Via LAN server

What types of viruses are there?• Logic bombs wait until a specific action is taken.• Time bombs activate on a certain date.• Trojan horses appear to be legitimate programs but when opened, damage software codes.• Worms burrow through and between networks to change or overwrite data.

22

33

11

Data Encryption

Modern encryption techniques use complex mathematical algorithms that scramble and lock confidential data contained in e-mail messages and binary files. There are two fundamental approaches to encryption: public-key encryption and conventional encryption. Both require user passwords. Conventional encryption uses two identical or symmetrical keys that both the sender and the recipient have. Public-key encryption uses two different keys to encrypt and decrypt files. The advantage is that only one key needs to be kept secure and that key doesn’t need to be shared.

Public-Key Encryption (Asymmetrical)

Conventional Encryption (Symmetrical)

File encrypted with public key Locked file sent to recipient File decrypted with secure key

File encrypted Locked file sent to recipient File decrypted with identical key

Percentage of Software Piracy around the World

Source : Software Publishers Association & IDC Corp., 1994

The Software Publishers Association (SPA) estimates that the total loss of business application software to piracy in 1994 was $8.1 billion. This was 49% of the total worldwide market. In some countries up to 98% of software used is an illegal copy. These figures are for business applications and do not include illegal copying of operating systems, education, entertainment, or personal productivity software.

Australia - 39%

Japan - 56%

China - 98%

United States - 25%

Canada - 26%

Mexico - 67%

Russia - 95%

Brazil - 74% South Africa - 33%

Germany - 31%

India - 87%

Hardware TechniquesDongle - An electronic device that connects to theparallel port. The software sends signals to the dongleto detect its presence. If it is not there the program will not work.

Authorization button - Microchip memories in button-shaped stainless steel cans. The chips contain missing but critical information to make the software operate.

Methods of Software Copy Protection

Software TechniquesFormatting - Manufacturers can format diskswith special equipment so they can't be copied using ordinary controllers and drives.

Password - Software distributed on CD-ROMs often use encryption, which asks the user for a password or key to unlock the program.

Software protection

Dongle

The Future of Computing Parallel Processing

Deep Blue

Pathfinder and Sojourner on Mars

Parallel processing subdivides the processing workload with multiple processors, enabling a computer to complete a task in shorter time. Examples of parallel processing computers include Cray supercomputers, IBM’s chess master Deep Blue, and NASA’s Mars Pathfinder.

Cray supercomputer

Society and the Future of ComputingTelecommuting

Since the word was first coined over 20 years ago, telecommuting has grown to be an increasingly viable alternative work structure that not only increases productivity but lowers operating costs and worker turnover as well.

Advantages• Greater employee retention and lower turnover• Reduces traffic congestion and taxes for road repair and new highway construction• Reduces absenteeism • Reduces pollution

Disadvantages• Requires greater discipline and self-motivation• Greater number of distractions at home• Reduced on-site interaction with clients and coworkers

VRML - Virtual Reality Machine Language

VRML is an industry standard that enables the development of interactive 3-D content and applications that can be deployed regardless of operating system, microprocessor brand or rendering technology. VRML 2.0 is based on the Silicon Graphics Moving Worlds proposal and is supported by small companies and big companies alike, including Netscape, Microsoft, Sony, Apple, and IBM. Many web sites, including NASA’s Pathfinder web site, contain VRML models that enable the viewer to gain a better grasp of the mechanics and construction of machines and vehicles. The viewer can rotate and move objects on screen in any direction, as well as zoom in and out to gain a better view from any angle.

Pathfinder and Sojourner VRML models

Sojourner VRML model