Computer Currents:

1. From Calculation to Communication 1 Computer Currents:

2. Learning Objectives • Characterize what a computer is and What it does • Describe several ways computers play play a critical role in modern life • Discuss the circumstances and ideas that led to the development of the modern computer • Describe several trends in the evolution of modern computers  2001 Prentice Hall

3. Learning Objectives • Comment on the fundamental difference between computers and other machines • Explain the relationship between hardware and software • Outline the four major types of computers in use today and describe their principal use  2001 Prentice Hall

4. Chapter Outline “Consider the past and you shall know the future.” Chinese Proverb • Living without Computers • Computers in Perspective: An Evolving Idea • Computers Today: A Brief Taxonomy • Computer Connections: The Internet Revolution • Living with Computers  2001 Prentice Hall

5. Living Without Computers Do you realize the implications of computers in your every day life?  2001 Prentice Hall

6. Input documents Processing elements Print materials Information-Processing Machine  2001 Prentice Hall

7. The First Real Computers Inventors of the first real computers include: Konrad Zuse John Atanasoff Howard Aiken John Mauchly & J. Presper Eckert  2001 Prentice Hall

8. Konrad Zuse Germany, 1939 “I was too lazy to calculate and so I invented the computer.” Zuse’s computer was built with electric relays and eventually vacuum tubes.  2001 Prentice Hall

9. John Atanasoff USA, 1939 Atanasoff-Berry Computer (ABC) This computer was builtwith vacuum tubes andbased on binary arithmetic. It was never completed.  2001 Prentice Hall

10. Howard Aiken USA, 1944 The Mark I was the largest electromechanical calculator ever built. It was built with electromechanical relays and followed instructions punched in paper tape.  2001 Prentice Hall

11. 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.  2001 Prentice Hall

12. Evolution and Acceleration • First Generation • Vacuum tubes • Second Generation • Transistors • Third Generation • Integrated circuit • Fourth Generation • Microprocessor  2001 Prentice Hall

13. 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  2001 Prentice Hall

14. 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  2001 Prentice Hall

15. Third-Generation Computers • Late 1960s • Silicon “chips” used as switches • Dramatic reduction in size and cost • Significant increases in reliability, speed, and efficiency  2001 Prentice Hall

16. Moore’s Law • In 1965, Moore predicted that the power of a silicon chip of the same size would double about every 18 months • This prediction has been remarkable accurate ever since.  2001 Prentice Hall

17. Fourth-Generation Computers • 1970s to present • Switches of previous generations reduced to microprocessor • Cost dropped so much that “hobbyists” could own them  2001 Prentice Hall

18. A Brief Taxonomy • Mainframes • Supercomputers • Workstations • Personal Computers • Portable Computers • Embedded Computer • Special-Purpose Computers  2001 Prentice Hall

19. Multi-User Computers Supercomputers… - the most powerful computers made - often called high-performance computer  2001 Prentice Hall

20. Multi-User Computers Mainframes… allow several users access to the same computer through timesharing • Minicomputers… • smaller and less expensive than mainframes  2001 Prentice Hall

21. Single-User Computers Workstations… the power of a minicomputer but less expensive.  2001 Prentice Hall

22. Single-User Computers Personal Computers (PC)… dedicated to serving one user  2001 Prentice Hall

23. Portable Computers • Palmtop • computers that are pocket-sized; power is not lost over portability Laptop • computers with flat screens, that are battery-operated and lightweight  2001 Prentice Hall

24. Special-Purpose Computers Special-Purpose… often attached to sensors to measure and/or control the physical environment Embedded… used to enhance consumer goods :wristwatch, game machine, stereo, oven …  2001 Prentice Hall

25. Special-Purpose Computers Firmware -When a program is immortalized on a silicon chip • a hybrid of hardware and software  2001 Prentice Hall

26. Computer Connections • Network revolution • Another information technology revolution • The beginning of the interpersonal computing era • Start from ARPANET in 1969: A few visionary computer scientists and engineers, with financial backing from the U.S. government, built an experimental network. It become the Internet.  2001 Prentice Hall

27. 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  2001 Prentice Hall

28. The Internet Explosion • A network of networks • Immense source of information • Electronic mail • Audio/Video links • Multimedia simulations • On-line transactions • World Wide Web  2001 Prentice Hall

29. Electronic Mail (e-mail) “The great success of the Internet is not technical, but its human impact.” Dave Clark 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  2001 Prentice Hall

30. 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  2001 Prentice Hall

31. World Wide Web Enter a Web page’s unique address (URL) to go to the Web page http://www.prenhall.com.beekman  2001 Prentice Hall

32. World Wide Web Click a hot link to jump to different Web pages  2001 Prentice Hall

33. To find information • Explore research material • To get instant answers The Internet Culture Why do people connect to the Internet?  2001 Prentice Hall

34. To shop • Play games • Track stocks The Internet Culture  2001 Prentice Hall

35. 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  2001 Prentice Hall

36. 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  2001 Prentice Hall

37. Connecting to the Internet • Direct connection • One that’s hard wired through an organization • Indirect connection • Telephone system • Cable TV connection • Wireless connection  2001 Prentice Hall

38. Living with Computers • What do you really need to know about computers and information technology? • Explanations? • Applications? • Implications?  2001 Prentice Hall

39. Clarifying Technology Learn basic concepts of hardware and software  2001 Prentice Hall

40. Word processing anddesktop publishing Spreadsheets anddatabases Computer graphics,multimedia and hypermedia Telecommunication and networking Artificial intelligence General problem-solving Programming languages Computers in Action Learn about the variety of software available:  2001 Prentice Hall

41. Social and Ethical Issues • Threat to personal privacy • Hazards of high-tech crime Learn about the impact of computers on your life: • Risk of computer failures • Threat of automation and dehumanization of work • Abuse of information as a tool of political & economic power • Protecting intellectualproperty  2001 Prentice Hall

42. Social and Ethical Issues • Blurring of reality • Evolution of intelligence • Emergence of bio-digital technology • Long-term potential risks • Technology dependence (remember the Y2K bug?) • The Death of privacy  2001 Prentice Hall