Copyright © 2003 by Prentice Hall Computers: Tools for an Information Age Chapter 1 Computers: Tools for an Information Age

2Copyright © 2003 by Prentice Hall Fundamental Characteristics SpeedReliability Storage Capability By-products

3Copyright © 2003 by Prentice Hall Benefits of Computers Productivity Workers use computers to do their jobs faster and better Workers use computers to do their jobs faster and better Many processes can be more efficiently controlled by computers Many processes can be more efficiently controlled by computers Decision Making Helps decision makers sort out financial, geographical, and logistical factors Helps decision makers sort out financial, geographical, and logistical factors Cost Reduction Helps hold down costs of labor, energy and paperwork Helps hold down costs of labor, energy and paperwork Return

4Copyright © 2003 by Prentice Hall Computer System Components Hardware Equipment associated with the system Equipment associated with the systemSoftware Instructions that tell the hardware what to do Instructions that tell the hardware what to doPeople Computer programmer: writes software Computer programmer: writes software User: purchases and uses software User: purchases and uses software Often called end-user

5Copyright © 2003 by Prentice Hall Hardware: The Basic Components of a Computer What is a Computer? What is a Computer? Four primary components: Input devices Input devices Input devices Input devices Processor Processor Processor Output devices Output devices Output devices Output devices Storage Storage Storage

6Copyright © 2003 by Prentice Hall What Is a Computer? A machine that can be programmed to accept data, process it into useful, and store it away A machine that can be programmed to accept data, process it into useful information, and store it away Data: raw facts representing people and events Data: raw facts representing people and events Information: data that is organized, meaningful, and useful Information: data that is organized, meaningful, and useful Return

7Copyright © 2003 by Prentice Hall Input: What Goes In Input: the data put into the computer for processing Common input devices: Keyboard Keyboard Keyboard Mouse Mouse Mouse Scanner Scanner Scanner Return

8Copyright © 2003 by Prentice Hall Keyboard Most common input device Generates electrical signals which are translated into characters Generates electrical signals which are translated into characters Return

9Copyright © 2003 by Prentice Hall Mouse Moves over a flat surface Movement of mouse ball causes corresponding movement of pointer on screen Movement of mouse ball causes corresponding movement of pointer on screen Return

10Copyright © 2003 by Prentice Hall Scanner Reads special letters, numbers, and symbols Wand reader, bar code reader often used in stores Wand reader, bar code reader often used in stores Flatbed and sheet-fed scanners scan pictures or printed documents Flatbed and sheet-fed scanners scan pictures or printed documents Return

11Copyright © 2003 by Prentice Hall The Processor and Memory: Data Manipulation Processor Also called central processing unit (CPU) Also called central processing unit (CPU) MemoryMemory (primary storage) Memory Closely related to, but distinct from processor Closely related to, but distinct from processor Provides temporary storage Provides temporary storage Return

12Copyright © 2003 by Prentice Hall Primary Storage Used to temporarily hold data After it is retrieved from input device and before it is processed After it is retrieved from input device and before it is processed After it is processed and before it is released to output device After it is processed and before it is released to output device Temporary (volatile) storage Data in memory lost if power is lost or program closed Data in memory lost if power is lost or program closed Return

13Copyright © 2003 by Prentice Hall The Processor Center of activity in the computer Consists of electronic circuits Consists of electronic circuits Interprets and executes program instructions Communicates with input, output, and storage devices Actually transforms data into information Return

14Copyright © 2003 by Prentice Hall Output: What Comes Out Output: the result produced by the CPU Common forms of output: text, numbers, graphics, and sounds Common output devices: Screen (monitor): can display text, numbers, photographs, even video, in full color Screen (monitor): can display text, numbers, photographs, even video, in full color Printer: produces printed reports as instructed by a program Printer: produces printed reports as instructed by a program Return

15Copyright © 2003 by Prentice Hall Secondary Storage Provides long-term storage Separate from memory Separate from memory Common media Magnetic disks Magnetic disks Magnetic disks Magnetic disks Optical disks Optical disks Optical disks Optical disks Magnetic tape Magnetic tape Magnetic tape Magnetic tape Return

16Copyright © 2003 by Prentice Hall Magnetic Disks The most common storage media Diskette: 3.5” flexible diskette in plastic case Diskette: 3.5” flexible diskette in plastic case Hard Disk: more storage capacity and faster access than diskette Hard Disk: more storage capacity and faster access than diskette Return

17Copyright © 2003 by Prentice Hall Optical Disks Use a laser beam to read large volumes of data inexpensively CD-ROMs CD-ROMs DVD-ROMs DVD-ROMs Return

18Copyright © 2003 by Prentice Hall Peripheral Devices All hardware devices attached to the computer Includes all input, output, and storage devices Includes all input, output, and storage devices

19Copyright © 2003 by Prentice Hall Networking Network: a system that uses communications equipment to connect computers and their resources Common network tools: Local Area Network (LAN) Local Area Network (LAN) Local Area Network (LAN) Local Area Network (LAN) Modem Modem Modem Electronic mail Electronic mail Electronic mail Electronic mail

20Copyright © 2003 by Prentice Hall Local Area Network Personal computers in an office are connected so users can communicate Users can operate computers independently Users can operate computers independently Can share resources and exchange data Can share resources and exchange data Return

21Copyright © 2003 by Prentice Hall Modem A device that allows users to communicate with other computers over telephone lines Required when you don’t have a digital connection such as DSL or a cable modem Required when you don’t have a digital connection such as DSL or a cable modem Return

22Copyright © 2003 by Prentice Hall Electronic Mail ( ) Send and receive messages electronically Can send text, pictures, links to Web sites Can send text, pictures, links to Web sites Can attach files for collaboration Can attach files for collaboration Messages stored in computer “mailbox” Return

23Copyright © 2003 by Prentice Hall The Internet The largest and most far-flung network Connects users worldwide Connects users worldwide Not actually a network, but a collection of thousands of networks Not actually a network, but a collection of thousands of networks

24Copyright © 2003 by Prentice Hall Getting Connected To access the Internet, connect to a computer To access the Internet, connect to a server computer Server receives, processes, and transmits information Server receives, processes, and transmits information Computers use a standard to communicate standard Need an Internet Service Provider (ISP) Internet Service Provider Internet Service Provider

25Copyright © 2003 by Prentice Hall Internet Service Providers The owner of a server computer Charges a fee for access to the Internet Charges a fee for access to the Internet Fee can provide unlimited access or be based on usage Provides the user a means to connect to the server Once connected, you can connect to the Internet and all other server computers Once connected, you can connect to the Internet and all other server computers Return

26Copyright © 2003 by Prentice Hall Computer Protocols Provides a standard way to communicate with other computers Transmission Control Protocol/Internet Protocol (TCP/IP) used on the Internet Transmission Control Protocol/Internet Protocol (TCP/IP) used on the Internet Allows different types of computers to share data Allows different types of computers to share data Return

27Copyright © 2003 by Prentice Hall Getting Around the Internet Began as a means for Department of Defense and its research institutions to share information Information was text-only Information was text-only Commands to navigate were obscure Commands to navigate were obscure Now, much more visually based Use browser to explore the Internet Use browser to explore the Internetbrowser World Wide Web World Wide Web World Wide Web World Wide Web

28Copyright © 2003 by Prentice Hall Browser Software that allows you to use a mouse to explore the Internet Click on screen text and/or graphics to move to different locations Click on screen text and/or graphics to move to different locations Most commonly used to explore the World Wide Web Most commonly used to explore the World Wide WebWorld Wide WebWorld Wide Web Return

29Copyright © 2003 by Prentice Hall The World Wide Web A subset of the Internet Actually, a standard for displaying and transmitting information Actually, a standard for displaying and transmitting information Web site: a location on the Web Home page: the main page of a Web site Home page: the main page of a Web site Return

30Copyright © 2003 by Prentice Hall Classification of Computers Personal Computers Personal Computers Notebook Computers Notebook Computers Handheld Computers Handheld Computers Supercomputers

31Copyright © 2003 by Prentice Hall Personal Computers Desktop computers Also known as PCs, microcomputers, or home computers Also known as PCs, microcomputers, or home computers Broken down into three categories: categories Low-end computers Low-end computers Fully-powered personal computers Fully-powered personal computers Workstations Workstations Network computer Central processing unit and minimal memory Central processing unit and minimal memory Designed to be used on a network Designed to be used on a network Sometimes called thin client Return

32Copyright © 2003 by Prentice Hall PC Categories Low-end computers Fine for home users, word processing, simple games, Internet access Fine for home users, word processing, simple games, Internet access Fully powered computers Good for heavy use of graphics, programming, or action-oriented games Good for heavy use of graphics, programming, or action-oriented gamesWorkstations Very high-end computers used by engineers, financial traders, and graphic designers Very high-end computers used by engineers, financial traders, and graphic designers Return

33Copyright © 2003 by Prentice Hall Notebook Computers Small, lightweight computers Capabilities approach that of desktop computers Similar processing and memory Similar processing and memory Most have hard disk, and diskette or CD-ROM drive Most have hard disk, and diskette or CD-ROM drive Typically more expensive than comparable desktop computers Return

34Copyright © 2003 by Prentice Hall Handheld Computers Personal Digital Assistant (PDA) Keeps track of appointments, contacts, etc. Keeps track of appointments, contacts, etc. Accepts input with hand-held stylus Accepts input with hand-held stylus Pocket PC Offers capabilities of PDAs, plus the ability to run stripped-down versions of software such as word processing and spreadsheets Offers capabilities of PDAs, plus the ability to run stripped-down versions of software such as word processing and spreadsheets Return

35Copyright © 2003 by Prentice Hall Supercomputers The fastest and most powerful computers Capable of processing trillions of instructions per second Capable of processing trillions of instructions per second Used for very sophisticated applications requiring mammoth data manipulation: Weather forecasting Weather forecasting Weapons research Weapons research Special effects for movies Special effects for movies Return

36Copyright © 2003 by Prentice Hall Personal Computer System