Computer Science: An Overview (11th Edition) PDF

Chapter 0: Introduction Computer Science: An Overview (11th Eleventh Edition) by J. Glenn Brookshear Copyright © 2012 Pears...

Chapter 0: Introduction Computer Science: An Overview (11th Eleventh Edition) by J. Glenn Brookshear Copyright © 2012 Pearson Education, Inc. Modified by: Ghada Ali Shommo_‫ـ‬Jan 2023  Discovering Computers Fundamentals by Shelly&Vermaat Copyright © 2012 Pearson Education, Inc. 0-2 Chapter 0: Introduction  0.0 Overview  0.1 What is a computer  0.2 The Role of Algorithms  0.3 The History of Computing Machines  0.4The Science of Algorithms Copyright © 2012 Pearson Education, Inc. 0-3  0.0 Overview  In this preliminary chapter we: o Consider the scope of computer science. o Develop a historical perspective. o Establish a foundation from which to launch our study. Copyright © 2012 Pearson Education, Inc. 0-4  0.0 Overview ‫جمال‬/‫ختصص‬ Computer science is the discipline that seeks to build a scientific foundation for such topics as: computer design, computer programming, information processing, algorithmic solutions of problems, and the algorithmic process itself. ‫األسس‬ It provides the underpinnings for today’s computer applications as well as the foundations for tomorrow’s computing infrastructure. Copyright © 2012 Pearson Education, Inc. 0-5  What Is a Computer? A computer is an electronic device, operating under the control of instructions stored in its own memory Collects Produces data Processing information (input) (output) Information Processing Cycle Copyright © 2012 Pearson Education, Inc. 6 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  What Is a Computer? Discovering Computers Copyright © 2012 Pearson Education, Inc. Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  The Components of a Computer Input Device Allows you to enter data and instructions into a computer Hardware component that conveys information to one or more Output Device people Case that contains the electronic components of the computer System Unit that are used to process data Records (writes) and/or retrieves (reads) items to and from Storage Device storage media Enables a computer to send and receive data, instructions, and Communications information to and from one or more computers or mobile Device devices Copyright © 2012 Pearson Education, Inc. Discovering Computers 2012, © 2012 Course Technology, Cengage Learning8 Page 7 Copyright © 2012 Pearson Education, Inc. Figure 1-3 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning9  Networks and the Internet A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media Pages 10 -©112012 Pearson Education, Inc. Copyright 10 Figure 1-6 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  Networks and the Internet The Internet is a worldwide collection of networks that connects millions of businesses, government agencies, educational institutions, and individuals Page 11 © 2012 Pearson Education, Inc. Copyright 11 Figure 1-7 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  Networks and the Internet People use the Internet for a variety of reasons: Communicate Research and Shop Bank and Invest Online Trading Access Information Entertainment Download Videos Share Information Web Application Pages 12 - 13 Copyright © 2012 Pearson Education, Inc. Discovering Computers 2012, © 2012 Course Technology, Cengage Learning 12 Figure 1-8  Networks and the Internet A social networking Web site encourages members to share their interests, ideas, stories, photos, music, and videos with other registered users Discovering Computers 2012, © 2012 Course Technology, Page 14 © 2012 Pearson Education, Inc. Copyright Cengage Learning 13 Figure 1-9  Computer Software Software, also called a program, tells the computer what tasks to perform and how to perform them System Software Operating system Utility program Application Software Pages 15 -©162012 Pearson Education, Inc. Copyright 14 Figures 1-10 - 1-11 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  Computer Software Installing is the process of setting up software to work with the computer, printer, and other hardware Discovering Computers 2012, © 2012 Course Technology, Pages Cengage 16 - 17 Copyright © 2012 Pearson Education, Inc. Learning 15 Figure 1-12  Computer Software A programmer develops software or writes the instructions that direct the computer to process data into information Copyright Discovering © 2012 2012, Computers Pearson © Education, 2012 CourseInc. Technology, Cengage Learning 16  Categories of Computers Personal computers Mobile computers and mobile devices Game consoles Servers Mainframes Supercomputers Embedded computers Page 19 © 2012 Pearson Education, Inc. Copyright 17 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  Personal Computers A personal computer can perform all of its input, processing, output, and storage activities by itself Two popular architectures are the PC and the Discovering Computers 2012, © 2012 Course Technology, Cenga Apple – Desktop computer Pages 19 - 20 Copyright © 2012 Pearson Education, Inc. 18 Figures 1-15 - 1-16  Mobile Computers and Mobile Devices Mobile Mobile Computer Device Personal computer Computing device you can carry from small enough to hold place to place in your hand Examples include Examples include smart phones and notebook computers, PDAs, e-book laptop computers, readers, handheld netbooks, ultra-thins, computers, portable and Tablet PCs media players, and digital cameras Pages 20 -©232012 Pearson Education, Inc. Copyright 19 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning  Mobile Computers and Mobile Devices Notebook computer Tablet PC Smart phones and PDAs E-book reader Pags 20 - 22 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning Copyright © 2012 Pearson Education, Inc. 20 Figures 1-17 – 1-20  Mobile Computers and Mobile Devices Handheld computer Portable media player Digital camera Pages 22 - 23 Discovering Computers 2012, © 2012 Course Technology, Cengage Learning Copyright © 2012 Pearson Education, Inc. 21 Figures 1-21 – 1-23  Game Consoles A game console is a mobile computing device designed for single-player or multiplayer video games Page 24 Computers Discovering Copyright 2012, ©Education, © 2012 Pearson 2012 CourseInc. Technology, Cengage Learning 22 Figure 1-24  Servers A server controls access to the hardware, software, and other resources on a network It provides a centralized storage area for programs, data, and information Page 25 © 2012 Pearson Education, Inc. Discovering Computers 2012, © 2012 Course Technology, Cengage Learning Copyright 23 Figure 1-25  Mainframes A mainframe is a large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously Page 25 CopyrightComputers Discovering © 2012 Pearson Education, 2012, © Inc.Technology, Cengage Learning 2012 Course 24 Figure 1-26  Supercomputers A supercomputer is the fastest, most powerful computer – Fastest supercomputers are capable of processing more than one quadrillion instructions in a single second Page 25 CopyrightComputers Discovering © 2012 Pearson Education, 2012, © Inc.Technology, Cengage Learning 2012 Course 25 Figure 1-27  Embedded Computers An embedded computer is a special- purpose computer that functions as a component in a larger product. Examples: Process Controllers and Consumer Electronics Robotics Mobile and digital telephones Remote monitoring systems Digital televisions Power monitors Cameras Machine controllers Video recorders Medical devices DVD players and recorders Answering machines Page 26 © 2012 Pearson Education, Inc. Discovering Computers 2012, © 2012 Course Technology, Cengage Learning Copyright 26  0.2 The Role of Algorithms  The most fundamental concept of computer science – that of an algorithm.  Algorithm: is a set of steps that defines how a task is performed. Example Copyright © 2012 Pearson Education, Inc. 0-27 Terminology Algorithm: is a set of steps that defines how a task is performed. Program: A representation of an algorithm. Programming: The process of developing a program. Software: Programs and algorithms. Hardware: Equipment. Copyright © 2012 Pearson Education, Inc. 0-28 History of Algorithms The study of algorithms was originally a subject in mathematics. Early examples of algorithms – Long division algorithm – Euclidean Algorithm(*greatest common divisor) Gödel's Incompleteness Theorem: Some problems cannot be solved by algorithms. Copyright © 2012 Pearson Education, Inc. 0-29 Figure 0.2 The Euclidean algorithm for finding the greatest common divisor (gcd) Compute the gcd of Example 32 and 24? Step 1 M 32 N 24 Step 2  Divide 32 by 24 to get a quotient of 1 and a remainder of 8. (R = 8) Step 3 M 24  If R is not 0, (R = 8) N 8  Then divide 24 by 8 to get a quotient of 3 and a remainder of 0. (R = 0)  8 is the gcd of 32 and 24. Copyright © 2012 Pearson Education, Inc. 0-30  0.3 The History of Computing Machines  Early Computing Devices  Early Data Storage  Early Computers Copyright © 2012 Pearson Education, Inc. 0-31  0.3 The History of Computing Machines  Early Computing Devices: ‫حلقات دائرية‬/‫خرز‬ – Abacus: positions of beads represent numbers – Gear-based machines (1600s-1800s) Positions of gears represent numbers Inventors: Blaise Pascal, Wilhelm Leibniz, Charles Babbage Copyright © 2012 Pearson Education, Inc. 0-32  0.3 The History of Computing Machines  Early Computing devices:  Abacus: Figure 0.3 An Abacus Copyright © 2012 Pearson Education, Inc. 0-33  0.3 The History of Computing Machines  Early Computing devices:  Abacus: – One of the earlier computing devices(used in the early Greek and Roman civilization). ‫حلقات دائرية‬/‫خرز‬ – The beads are moved back and forth and their positions represent stored values. – Positions of beads represent numbers. – The machine relies on the human operator to create a complete computational machine. Copyright © 2012 Pearson Education, Inc. 0-34  0.3 The History of Computing Machines  Early Computing devices:  Gear-based machines (1600s-1800s) Positions of gears represent numbers.  Pascal’s machine: built to perform only addition operations.  Leibniz’s machine: offered a variety of arithmetic operations.  Babbage’s machines:  Designed to read instructions through paper cards.  Performed various computations. Copyright © 2012 Pearson Education, Inc. 0-35  0.3 The History of Computing Machines  Early Computing devices:  Gear-based machines (1600s-1800s)  Pascal’s and Leibniz’s machines: the output was achieved by observing the final gear positions.  Babbage’s machines: print the results of computations on paper and reduce the possibility of transcription errors. Copyright © 2012 Pearson Education, Inc. 0-36  0.3 The History of Computing Machines  Early Data Storage:  Punched Cards ‫البطاقات املثقوبة‬ First used by Joseph Jacquard in (1801) to )‫حنت‬/‫أمناط(رسم‬ store patterns during weaving process(in large thick cards made of wood [or cardboard]). Storage of programs in Babbage’s Analytical Engine. Popular through the 1970’s.  Gear positions Positions of gears represent numbers. Copyright © 2012 Pearson Education, Inc. 0-37  0.3 The History of Computing Machines  Early Computers: ‫آلة كهروميكانيكية‬ Based on electromechanical machine: – 1940: by George Stibitz at Bell Laboratories – 1944: Mark I: by Howard Aiken and a group of IBM engineers at Harvard University. Based on vacuum tubes – 1937-1941: by Atanasoff-Berry at Lowa State – 1940s: Colossus: secret German code-breaker – 1940s: ENIAC: John Mauchly & J.Eckert at University of Pennsylvania. Copyright © 2012 Pearson Education, Inc. 0-38  0.3 The History of Computing Machines  Early Computers: Figure 0.4 The Mark I computer (1944) Copyright © 2012 Pearson Education, Inc. 0-39  0.3 The History of Computing Machines  Early Computers:  The history of computing machines has been closely linked to advancing technology, including  The invention of transistors;  Development of complete circuits constructed as single units called “integrated circuits”;  With these development, the room-sized machines of the 1940s were reduced to the size of single cabinets. Copyright © 2012 Pearson Education, Inc. 0-40  0.3 The History of Computing Machines  Personal Computers: ‫اهلواة‬ – First used by hobbyists(built from combinations of chips). – IBM introduced the PC in 1981: Accepted by business community. Became the standard hardware design for most desktop computers. Most PCs use software from Microsoft. Currently, the term PC is used with generic term “desktop” or “Laptop”. Copyright © 2012 Pearson Education, Inc. 0-41  0.3 The History of Computing Machines  Into the Millennia.. ‫عرب آالف السنني‬ As twentieth century; the ability to connect individual computers in world-wide system called the “Internet”. Internet communications: – World Wide Web – Search Engines: to make the information accessible on the Web (ex.Google,Yahoo, and Microsoft). ‫أجهزة حاسوب صغرية جدا‬  Today, “tiny computers” embedded within various devices(ex. GPS in automobile engines, Smartphone, etc.). Copyright © 2012 Pearson Education, Inc. 0-42  0.4The Science of Algorithms  The science of algorithms draws from other subjects, including:  Mathematics  Engineering  Biology  Psychology  Business Administration Copyright © 2012 Pearson Education, Inc. 0-43  0.4 The Science of Algorithms  Central Questions of Computer Science:  Which problems can be solved by algorithmic processes?  How can algorithm discovery be made easier?  How can techniques of representing and communicating algorithms be improved?  How can characteristics of different algorithms be analyzed and compared? Copyright © 2012 Pearson Education, Inc. 0-44  0.4 The Science of Algorithms  Central Questions of Computer Science (continued):  How can algorithms be used to manipulate information?  How can algorithms be applied to produce intelligent behavior?  How does the application of algorithms affect society? Copyright © 2012 Pearson Education, Inc. 0-45  0.4 The Science of Algorithms Figure 0.5 The central role of algorithms in computer science Copyright © 2012 Pearson Education, Inc. 0-46