Welcome to CMPE003 Personal Computer Concepts: Hardware and Software Winter 2003 UC Santa Cruz Instructor: Guy Cox

Computers: Tools for an Information Age Chapter 1 – Part b Computers: Tools for an Information Age

Forging a Computer-Based Society Traditional Cornerstones of Economy:  Land  Labor  Capital New Economic Element:  Information

Computers are all around! Grocery store School Library Bank Mail We interact with computers everyday! We interact with computers everyday!

Fundamental Characteristics Speed Reliability Storage Capability By-products (or Benefits) By-products

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

Chapter Objectives Describe the three fundamental characteristics of computers  Speed, reliability & storage Describe at least four areas of society in which computers are used Identify the basic components of a computer system:  input, processing, output, and storage (IPOS) List some common input, output, and storage media Distinguish raw data from information Describe the significance of computer networks Explain the significance of the Internet Explain the various classifications of computers

Computer System People Software Hardware

People Hardware Engineers –  People who design and build computers Software Engineers (programmers) –  People who design and write software programs Users or End-users –  People who make use of the computer’s capabilities

Software Programs Set of instructions that directs the hardware to do a required task and produce the desired results

Hardware – Basic Components of a Computer

What Is a Computer? 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  Information: data that is organized, meaningful, and useful

Functions in a Computer System What is a computer? Four primary components:  Input devices  Processor  Output devices  Storage

Input: What Goes In Input: the data or commands put into the computer for processing Common input devices:  Keyboard  Mouse  Scanner  Microphone  Camera

Keyboard Most common input device  Generates electrical signals which are translated into characters

Mouse Moves over a flat surface  Movement of mouse ball causes corresponding movement of pointer on screen

Scanner Reads special letters, numbers, and symbols  Wand reader, bar code reader often used in stores  Flatbed and sheet-fed scanners scan pictures or printed documents

The Processor and Memory: Data Manipulation Processor  Also called central processing unit (CPU) Memory (primary storage) Memory  Closely related to, but distinct from processor  Provides temporary storage

Primary Storage Used to temporarily hold data  After it is retrieved from input device and before it is processed  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

The Processor Center of activity in the computer  Consists of electronic circuits Interprets and executes program instructions Communicates with input, output, and storage devices Transforms data into information

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  Printer: produces printed reports as instructed by a program

Output devices Monitor or screen Text Numbers Symbols Art Photographs Video Printer Black and white Color Convert from electronic form to some other form May display the processed results Usable information Speakers Music CDs, DVDs

Secondary Storage Provides long-term storage  Separate from memory Common media  Magnetic disks Magnetic disks  Optical disks Optical disks  Magnetic tape Magnetic tape Caveat -- “Bit rot” Data can be lost or changed over time

Magnetic Disks The most common storage media  Diskette: 3.5” flexible diskette in plastic case  Hard Disk: more storage capacity and faster access than diskette

Optical Disks Use a laser beam to read large volumes of data inexpensively  CD-ROMs  DVD-ROMs

Magnetic Tape Stores large amounts of data inexpensively Often used for system backup

Peripheral Devices All hardware devices attached to the computer  Includes all input, output, and storage devices

Networking Network: a system that uses communications equipment to connect computers and their resources Common network tools:  Local Area Network (LAN)  Wide Area Network (WAN)  Modem  Electronic mail

Local Area Network (LAN) Personal computers in an office are connected so users can communicate  Users can operate computers independently  Can share resources and exchange data

Wide Area Network (WAN)  Wide area network (WAN) – connects computers over great distances A WAN may connect several LANs

The Internet The largest and most far-flung network  Connects users worldwide  Not actually a network, but a collection of thousands of networks No ownership No central source for services available No comprehensive index of what information is available

Internet Individuals Businesses Organizations Libraries Research labs Government Connects Everyone!

Electronic Mail ( ) Send and receive messages electronically  Can send text, pictures, links to Web sites  Can attach files for collaboration Messages stored in computer “mailbox”

Getting Connected To access the Internet, connect to a server computer  Server receives, processes, and transmits information Computers use a standard to communicatestandard Need an Internet Service Provider (ISP)Internet Service Provider

Home Connectivity Connect home PC to other computers  (Usually via an ISP) Use modem to convert signals between electronic (computer) and analog (voice) formats  Dial-up modem  ADSL modem  Cable modem

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

Internet Service Providers The owner of a server computer  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

Computer Protocols Provides a standard way to communicate with other computers  Transmission Control Protocol/Internet Protocol (TCP/IP) used on the Internet  Allows different types of computers to share data

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

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  Most commonly used to explore the World Wide WebWorld Wide Web

The World Wide Web A subset of the Internet  Actually, a standard for displaying and transmitting information Web site: a location on the Web  Home page: the main page of a Web site

Classification of Computers Personal Computers Notebook Computers Handheld Computers Midrange Computers Mainframes Supercomputers

Classifications of Computers Use the computer that fits your needs Based upon  Size  Speed  Cost  Portability  Number of simultaneous users supported  Available software  Typical use

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

PC Categories Low-end computers  Fine for home users, word processing, simple games, Internet access Fully powered computers  Good for heavy use of graphics, programming, or action- oriented games Workstations  Very high-end computers used by engineers, financial traders, and graphic designers

Notebook Computers Small, lightweight computers Capabilities approach that of desktop computers  Similar processing and memory  Most have hard disk, and diskette or CD-ROM drive Typically more expensive than comparable desktop computers

Handheld Computers Personal Digital Assistant (PDA)  Keeps track of appointments, contacts, etc.  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

Other Types of Computers Client/Servers  client processes requesting service from server processes  clients and servers running on the appropriate hardware and software Mainframes  High speed  More expensive  Used to process large amounts of data quickly Transaction processing  Support multiple users  Does server tasks Supercomputers  Fastest speed  Most expensive

Midrange Computers Multi-user computers designed to serve the needs of medium-sized organizations  Hundreds or thousands of users connected  Used for inventory, order-entry, and other company-wide applications Return

Mainframes Very large and powerful computers  Capable of processing billions of instructions per second  Capable of handling billions of characters of data Often used for applications with many users  Reservations systems  Large mail-order houses  servers Return

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