Chapter 1 Introduction to Operating System Part 1

1. Chapter 1Introduction to Operating SystemPart 1 F2032 Fundamental Of Operating System

2. Chapter Summary • At the end of this chapter, student will be able to: • Define operating system • List the use of operating system in computer system • List the evolution of operating system F2032 Fundamental Of Operating System

3. Introduction to Operating System (OS) • Software program that controls the hardware. • Definition of an operating system can be seen in four aspects: • A group of program that acts as an intermediary between a user and the computer hardware. • Controls and co-ordinates the use of computer resources among various application programs and user. • Acts as a manager • Allow the program to communicate with one another F2032 Fundamental Of Operating System

4. Introduction to Operating System (OS) • Basically, two types of software available: • System software - Groups of program that control the hardware • Application software - Groups of programs that used by the end-user for various applications such as text processing, spreadsheet, etc • OS categorized as system software - Build to act as an intermediary between user of a computer and computer hardware - Goal: Provide convenient and efficient environment for the user F2032 Fundamental Of Operating System

5. Introduction to Operating System (OS) User1 User2 User3 System and application programs Operating system Hardware Figure 1: Abstract view of the components of a computer system F2032 Fundamental Of Operating System

6. Introduction to Operating System (OS) • Functions: 1) Resource Sharing • The OS contains a set of algorithms that allocates resources to the programs executed on behalf of the user. • These resources include time, power, hardware, etc... 2) Control Program - The control program controls the operation of the application programs to prevent errors affecting other programs. 3) Provision of a Virtual Machine -This hides interfaces to I/O devices, filing systems, etc, and provides a programming interface for applications. 4) Kernel -The kernel is the only program resident all the time (all other applications are application programs). F2032 Fundamental Of Operating System

7. Introduction to Operating System (OS) • OS has three objectives: • Convenience - An OS make a computer more convenient to be used • Efficiency - An OS allows the computer system resources to be used in an efficient manner • Ability to evolve - An OS is constructed in such a way to as to permit the effective development, testing and introduction of new system function without at the same time interfering with service. F2032 Fundamental Of Operating System

8. History of Operating System (OS) • Operating systems have been evolving through the years. • The first true digital computer was designed by the English mathematician Charles Babbage (1792-1871). • Babbage spent most of his life and fortune trying to built his “analytical engine” but he never got it working properly. • It was a purely mechanical design and the technology of his day could not produce the wheels, gears, cogs and other mechanical parts to the high precision that he needed • Needless to say, the analytical engine did not have an operating system. F2032 Fundamental Of Operating System

9. History of Operating System (OS) First Generation (1945-1955): Vacuum Tubes and Plug boards • Mid-1940s - Howard Aiken (Harvard), John von Neumann (Princeton) , J. Presper Eckert and William Mauchley(Pennsylvania), and KonardZuse(Germany), among other, all succeeded in building calculating engines using vacuum tubes. • Machines were enormous, filling up entire rooms with tens of thousands of vacuum tubes, but were much slower than even the cheapest home computer available to day. • All programming was done in absolute machine language, often by wiring up plug boards to control the machine’s basic functions. F2032 Fundamental Of Operating System

10. History of Operating System (OS) First Generation (1945-1955): Vacuum Tubes and Plug boards • Early 1950- Routine had improved somewhat with the introduction of punched cards. - It was now possible to write programs on cards and read them in, instead of using plug boards -Otherwise the procedure was the same. F2032 Fundamental Of Operating System

11. History of Operating System (OS) Second Generation (1955-1965): Transistors and Batch Systems • Introduction of the transistor in the mid-1950s changed the picture radically. • Computers became reliable enough that they could be manufactured and sold to paying customer with the expectation that they would continue to function long enough to get some useful work done. F2032 Fundamental Of Operating System

12. History of Operating System (OS) How computer work during the second generation? 1st Step: To run job (example: program), programmer punch it on cards. 2nd Step: Programmer bring the cards to input room, hand it to operators. 3rd Step: Operator feed the card to computer. When the computer finished processing the job, operator would tear the output from printer and carried it to output room. Programmer would collect the output later. Disadvantages: Wasting of time Solution: Batch System F2032 Fundamental Of Operating System

13. History of Operating System (OS) How computer work during the second generation using batch system? • Collect tray full of jobs in input room. • Read them onto magnetic tape using small inexpensive computer (ex: IBM 1401) • After collecting batch of job, tape rewound , brought into machine room and mounted on tape drive. • Operator load special program (ancestor of today OS) which read first job from tape and run it. Output is written into second tape. • System automatically read the next job from tape and run it until the whole batch is processed and run. • Operator remove input and output tape and brought them to small computer (ex:IBM 1401) for printing. F2032 Fundamental Of Operating System

14. History of Operating System (OS) Third Generation (1955-1965): ICs and Multiprogramming • Early 1960 – Most manufacturer had two distinct, totally incompatible, produce lines. 1) Word Oriented - large scale scientific computer, example: IBM 7094 2) Character Oriented - commercial computer, example: IBM 1401 • IBM 360 – first major computer line to use small scale integrated circuit (IC) - major price/ performance advantage over second generation machine F2032 Fundamental Of Operating System

15. History of Operating System (OS) Third Generation (1955-1965): ICs and Multiprogramming • IBM 7094 – used a technique called multiprogramming. - Ability to process the next before the first job is finished. • Spooling (Simultaneous peripheral operation on line) - Ability to read jobs from cards onto disk - Whenever a running job is finished, OS could load a new job from disk into the now empty partition and run it F2032 Fundamental Of Operating System

16. History of Operating System (OS) Fourth Generation (1980-1990): personal computers • The development of LSI (Large Scale Integration) circuits introduce the use of personal computer - chips containing thousands of transistors on a square centimetre of silicon • Powerful personal computer use by business, universities and government are usually called workstations • 1980’s – Growth of personal computer running network OS and distributed OS. • Network OS – User can log in into remote machine and copy file from one machine to another - Each machine run it own local OS and has it own user F2032 Fundamental Of Operating System

17. History of Operating System (OS) Fourth Generation (1980-1990): personal computers • Distributed OS - Appears to its users as a traditional unit processor system, actually composed of multiple processor system F2032 Fundamental Of Operating System

18. Activity • List four functions of operating system. • What is the main technology evolved during the second generation (1955-1965)? • What is the main difference between the computer process using batch system and without a batch system during the second generation? F2032 Fundamental Of Operating System