From Calculation to Communication

Computer Currents:1

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Chapter Outline

• Living without Computers

• Computers in Perspective: An Evolving Idea

• Computers Today: A Brief Taxonomy

• Computer Connections: The Internet Revolution

• Living with Computers

“Consider the past and you shall know the future.”

Chinese Proverb

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Do you realize the implications of computers in your every day life?

Living Without Computers

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Information-Processing Machine

Input documents

Processingelements

Printmaterials

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Howard Aiken

John Atanasoff

Inventors of the first real computers include:

The First Real Computers

Konrad Zuse

John Mauchly & J. Presper Eckert

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“I was too lazy to calculate and so I invented the computer.”

Zuse’s computer was built with electric relays and eventually vacuum tubes.

Germany, 1939Konrad Zuse

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Atanasoff-Berry Computer (ABC)

This computer was builtwith vacuum tubes andbased on binary arithmetic.

It was never completed.

John AtanasoffUSA, 1939

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Howard AikenUSA, 1944

The Mark I was the largest electromechanical calculator ever built.

It was built with electromechanical relays and followed instructions punched in paper tape.

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John Mauchlyand Presper Eckert USA, 1945

Mauchly and Eckert built the ENIAC (Electronic Numerical Integrator and Computer).

The ENIAC was built with vacuum tubes and programmed with plug wires and switches.

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Evolution and Acceleration

• First Generation– Vacuum tubes

• Second Generation– Transistors

• Third Generation– Integrated circuit

• Fourth Generation– Microprocessor

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First-Generation Computers

• 1930s – 1940s

• Vacuum tubes used as switches

• Large computers

• Extremely slow by today’s standards

• Prone to frequent failure

• Includes the ABC, Mark I, ENIAC, UNIVAC, and others of similar design

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Second-Generation Computers

• 1950s – mid-1960s

• Transistors used as switches

• Smaller than vacuum-tube-built computers

• As much as a thousand times faster than first-generation computers

• More reliable and less expensive

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Third-Generation Computers

• Late 1960s

• Silicon “chips” used as switches

• Dramatic reduction in size and cost

• Significant increases in reliability, speed, and efficiency

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Fourth-Generation Computers

• 1970s to present

• Switches of previous generations reduced to microprocessor

• Cost dropped so much that “hobbyists” could own them

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A Brief Taxonomy

• Mainframes

• Supercomputers

• Workstations

• Personal Computers

• Portable Computers

• Embedded Computer

• Special-Purpose Computers

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Multi-User Computers

Supercomputers…

the most powerful computers made

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Multi-User Computers

Mainframes…

allow several users access to the same computer

Minicomputers…smaller and less expensive than mainframes

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Single-User Computers

Workstations…

the power of a minicomputer but less expensive.

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Single-User Computers

Personal Computers (PC)…

dedicated to serving one user

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Portable Computers

Laptop– computers with flat

screens, that are battery-operated and lightweight

Palmtop– computers that are

pocket-sized; power is not lost over portability

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Special-Purpose Computers

Special-Purpose…

often attached to sensors to measure and/or control the physical environment

Embedded…

used to enhance consumer goods

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Computer Connections

• Local Area Networks (LAN)– designed to share resources

– allow communication between users (usually in the same building)

• Wide Area Networks (WAN)– designed to share resources

– allow communication around the globe

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The Internet Explosion

• A network of networks

• Immense source of information

• Electronic mail

• Audio/Video links

• Multimedia simulations

• On-line transactions

• World Wide Web

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Electronic Mail (e-mail)

Why did E-mail lure people to the Internet?

– Availability

• software made it easy to use

– Speed

• messages can be created and delivered in minutes

“The great success of the Internet is not technical, but its human impact.”

Dave Clark

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World Wide Web

Web browsers help locate information on the Web

Information is stored on Web pages

A group of Web pages make up a Web site

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World Wide Web

Enter a Web page’s unique address (URL) to go to the Web page

http://www.prenhall.com.beekman

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Click a hot link to jump to different Web pages

World Wide Web

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The Internet Culture

Why do people connect to the Internet?

-To Find Information

-To Research Material

-To get instant answers

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The Internet Culture

To shop

Play Games

Check Stocks

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Internet Growth

• 1994? 3 million people connected

• Today? Hundreds of millions

• The United States leads the world in Internet activity– Approximately 1/3 of U.S. households

connected in 1999

– By 2003, twice that number is expected to be connected

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Impact of the Internet

• Companies are replacing mainframe and PC systems with Intranets– Private networks that allow people to transmit,

share and store information

• Computers may be used mostly to access Intranets and the Internet– IBM, Sun and Hewlett Packard are

developing computers to act as network terminals

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Connecting to the Internet

• Direct connection– One that’s hard wired through an

organization

• Indirect connection– Telephone system

• Cable TV connection

• Wireless connection

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Living with Computers

What do you really need to know about computers?

Implications?

Applications?

Explanations?

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Clarifying Technology

Learn basic concepts of hardware and software

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Computers in Action

– Word processing anddesktop publishing

– Spreadsheets anddatabases

– Computer graphics,multimedia and hypermedia

Learn about the variety of software available:

– Telecommunication and networking

– Artificial intelligence

– General problem-solving

– Programming languages

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– Threat to personal privacy

– Hazards of high-tech crime

Social and Ethical Issues

Learn about the impact of computers on your life:

– Risk of computer failures

– Protecting intellectualproperty

– Threat of automation – Dehumanization of

work– Abuse of information

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– Blurring of reality

– Evolution of intelligence

– Emergence of bio-digital technology

Social and Ethical Issues

– Technology dependence (remember the Y2K bug?)

– The Death of privacy

“For better and for worse, we’ll be coexisting with computers till death do us part.”

George Beekman