1. Lecture-I CS-120 Fall 2000 • Introducing the Course • Syllabus • Introduction to Computers • Introduction to Computer Science • Information, Algorithms and Programs • Information Technology • Computer as an idiot • Examples of Algorithms

2. Introducing the Course • Welcome to CS120 Computer Science Overview • This course aims at doing a comprehensive survey of the field of computer science • The textbook is “Computer Science: An Overview”, by J. Glenn Brookshear, Addison Wesley

3. Introduction • Let us go over the syllabus and then start the introductory topics

4. Topics • 1. Introduction to Computers, Main Components and Operating Systems • 2. Algorithms and Problem Solving • 3. Data Storage and Manipulation • 4. Programming • 5. Software Engineering • 6. Data Structures • 7. Computer Applications and Ethics in Computing

5. Introducing Computers • Computer is a device capable of performing computations • Computer can take logical decisions to choose between alternatives, something we do every day • Example: if price of item-selected is less than money-in-hand, then buy the item • else select something else

6. History of Computers • 2000BC Abacus used for computations • 1890 Hollerith designs electronic census reader and later founds IBM • 1939 J. Atanasoff designs first electronic digital computer • 1946 Von Neumann proposes stored program computer • 1977 Apple Computer launched • 1981 IBM PC launched

7. History of Computers • 1970 UNIX first version released • 1971 Pascal language developed • 1972 C language developed • 1973 Part of UNIX implemented in C • 1985 C re-implemented as C++ • 1996 C++ standard released

8. Types of Computers • Microcomputers (PDA, Lap-top, Desk-top and Workstation computers) • Minicomputers and Mainframes • Supercomputers

9. Hardware of Computers • Computers consist of • CPU (Data path and control) • Memory (Primary/Secondary) • Input devices • Output devices • What is a CD-Drive? • What is a SIMM? • What is a modem?

10. Computer Science • Computer Science is a relatively new discipline • It has advanced rapidly and growth of fields within computer science is enormous • Look at programming languages and techniques, computer networks, even the speed and power of PC’s

11. Computer Science • Formal Defintion: “It is a science of information handling and representation” • Another Definitions: “Computer Science is the study of those algorithms that transform information” • What is an algorithm?

12. Information, Algorithms and Programs • An algorithm is a precise sequence of steps that can be automated • Thus an algorithm can be entered into the computer using any programming language, resulting in a “program” • A computer can take logical decisions during execution of the programs • e.g. if Temp<10 don’t go jogging

13. Information, Algorithms and Programs • Due to the fact that computers can handle and process information, the use of computers has spread to all fields of human knowledge. • Computer can process sound and video data, financial and commerce data and scientific data, all with automated procedures

14. Computer as an idiot • A computer will only do whatever it is told to do, it is a faithful mindless slave. • If you ask the computer to do something, it will do it, whether right or wrong • If your program runs well but contains logical errors, you will get wrong results • If your program is ok but you feed wrong information, you will get wrong results

15. Computer as an idiot • Computers are very picky and small mistakes will confuse them easily • When you develop your Visual C++ programs, you will find out that the above statement is very true • A minor mistake, such as an additional comma or missing semicolon will drive the compiler crazy

16. Examples of Algorithms • Develop an algorithm to add three numbers together: • Add first two numbers; store the result at a temporary place • Recall the result from previous step and add the third number to it

17. Examples of Algorithms • Develop an algorithm to give driving directions from Fredonia to Cleveland • Go on Benett Road • Reach Thruway intersection • Take 90 West • Reach Cleveland downtown and exit at your selected road