Introduction to Computers By Dr Awad Khalil Computer Science Engineering Department 1 1 Overview of Computers Computer A device for computing Dr John Atanasoff 1st computer ENIAC 1946 at U of Penn Dr John Von Neumann Princeton Stored program concept Memory rather than wires and switches Computing History CSCI 106 Introduction to Computers 2 Overview of Computers Von Neumann architecture basis for today s computers VLSI Technology made computers affordable small and available to the public How programming has changed over time CSCI 106 Introduction to Computers 3 Development of Computers CSCI 106 Introduction to Computers 4 Development of Computers CSCI 106 Introduction to Computers 5 1 2 Computer Hardware Every computer is organized roughly into six parts CPU central processing unit Where decisions are made computations are performed and input output requests are delegated Main Memory Stores information being processed by the CPU Secondary Memory Stores data and programs CSCI 106 Introduction to Computers 6 Computer Hardware Input devices Allows people to supply information to computers Output devices Allows people to receive information from computers Network connection Modems Ethernet interface CSCI 106 Introduction to Computers 7 Basic Functional Components CSCI 106 Introduction to Computers 8 Basic Functional Components CSCI 106 Introduction to Computers 9 Computer Components CSCI 106 Introduction to Computers 10 Main Memory Address Contents 0 1 1024 27 2 354 005 75 62 CSCI 106 Introduction to Computers 11 Main Memory Stores programs data Types RAM ROM CSCI 106 Introduction to Computers 12 Main Memory CSCI 106 Introduction to Computers 13 Secondary Memory Storage Semi permanent data storage capability Tape or Disk Hard disk CD ROM Secondary memory has much more storage capacity CSCI 106 Introduction to Computers 14 CPU Brains of the computer Arithmetic calculations are performed using the Arithmetic Logical Unit or ALU Control unit decodes and executes instructions Arithmetic operations are performed using binary number system CSCI 106 Introduction to Computers 15 CPU Fundamental building block is a switch Switches are made from ultrasmall transistors Examples The Pentium processor contains about three million transistors The Pentium Pro has about 5 5 million transistors CSCI 106 Introduction to Computers 16 The Bus CSCI 106 Introduction to Computers 17 A microcomputer CSCI 106 Introduction to Computers 18 Input Output Devices Accessories that allow computer to perform specific tasks Receiving information for processing Return the results of processing Store information Common input and output devices Printer Joystick CD ROM Keyboard Monitor CSCI 106 Introduction to Computers 19 Printers CSCI 106 Introduction to Computers 20 Keyboard CSCI 106 Introduction to Computers 21 Computer Networks LAN Local area network Organizational WAN Wide area network Internet CSCI 106 Introduction to Computers 22 The Internet The Internet is the new server for millions of clients Internet technology is the most widely used and successful example of client server thin client fat server technology in use today The Internet has reached critical mass by allowing hundreds of millions of users to connect with each other thus making it inevitable that managers everywhere would see it as the new frontier to conquer in the quest for business profits and enhanced public services The use of Internet technologies facilitates the sharing of heterogeneous information in an environment that provides multiple benefits a fraction of the cost CSCI 106at Introduction to 23 Computers World Wide Web Introduced 1989 Developed by CERN European Laboratory for Particle Physics Web browser GUI Netscape IE CSCI 106 Introduction to Computers 24 The Web Building Blocks Internet World Wide Web WWW or Web Web Page HyperText Markup Language Hyperlink Web browser Static Web page Dynamic Web page Web server Web site HyperText Transfer Protocol CSCI 106 Introduction to Computers 25 The Web Building Blocks 1 Internet Worldwide network of computers connected together through a standard network protocol known as Transmission Control Protocol Internet Protocol or TCP IP You can think of the Internet as the highway on which data travel as in the phrase the information superhighway The terms Internet and World Wide Web are often used interchangeably but they are not synonyms 2 World Wide Web WWW or Web Worldwide network of servers that store collections of specially formatted files known as Web pages The Web is just one of many services provided by the Internet However it is the World Wide Web that truly opened the Internet to the World CSCI 106 Introduction to Computers 26 The Web Building Blocks 3 Web Page 5 Hyperlink A text document containing labels and special commands or tags written in a Markup Language HTML or XML 4 HyperText Markup Language Standard documentformatting language for Web pages Web pages are linked to each other that is each Web page can call other Web pages creating the effect of a web Because this link can connect to different types of documents such as text graphics animated graphics video and audio it is known as a hyperlink CSCI 106 Introduction to Computers 27 The Web Building Blocks 6 Web browser 7 Static Web page The end user application used to browse or navigate jump from page to page through the Web The browser is a graphical interface that runs on the client computer and its main function is to display Web pages The Web browser e g Netscape Navigator Internet Explorer requests Web pages from the Web server A Web page whose contents remain the same when viewed in a browser unless the page is manually edited An example of a static Web page is a standard price list posted by a manufacturer 8 Dynamic Web page A Web page whose contents are automatically created and tailored to an end user s needs each time the end user requests the page For example an end user can access a Web page that displays the latest stock selections entered by that end user CSCI 106 Introduction to Computers 28 The Web Building Blocks 9 Web server 11 A specialized application whose only function is to listen for clients requests and to send the requested Web page s HyperText Transfer Protocol The standard protocol used by the Web browser and Web server to communicate 10 Web site Term used to refer to the Web server and the collection of Web pages stored on the local hard disk of the server computer or an accessible shared directory