Introduction to operating system

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2. o An OS is an interface between userand hardware of a computer system.o An OS also called as a ResourceManager.o OS is in charge of a system so all therequests to use the resources need to gothrough OS. 2 3. o To make the computer system convenient touse.o To use the computer hardware in an efficientmanner.o To provide an environment in which a user may execute programs. 3 4. o Memory managemento Process managemento Device managemento Information managemento Protectiono Error Handling 4 5. o Memory management The o/s keeps track of the memory, what parts are in use and by whom. 5 6. o Process managementThe o/s keeps track of processorsand the status of processes. Itdecides who will have a chanceto use the processor.6 7. o Device management The o/s keeps track of the devices, channels, control units and decides what is an efficient way to allocate the device.7 8. O/S keeps track of the information, its location, use, status etc. and decides who gets use of the resources, enforce protection requirementso Information management 8 9. An o/s is to protect the user fromunauthorized access of his files ordata. And also it should protectitself from userso Protection9 10. An o/s must respond to errors bytaking the appropriate actions.o Error Handling 10 11. STRUCTURE OF AN OPERATING SYSTEMUsers Application Programs Operating System Computer Hardware11 12. o Hardware - Physical components of acomputer.o Software Set of computer programs. 12 13. System Programs Application Programsoo Which managesWhich manages oo Which solveWhich solve the operations ofthe operations ofproblems forproblems for the computerthe computer their userstheir users13 14. First generation: 1945 1955 Vacuum tubes Plug boards Second generation: 1955 1965 Transistors Batch systems Third generation: 1965 1980 Integrated circuits Multiprogramming Fourth generation: 1980 present Large scale integration Personal computers14 15. Batch Operating System Time-Sharing Operating System Real-Time Operating System Multiprogramming Operating System15 16. Batch Operating SystemBatch operating system is the one whichanalyzes our input and groups them intobatches .That is data in each batch is ofsimilar characteristics. And then it performsoperation on each individual batch.16 17. Computer provides computing services to several or many users concurrently on-line. Various users are sharing the central processor, the memory and other resources of the computer system. The user has full interaction with the program during its execution. Time-Sharing Operating System17 18. A real-time operating system aims at executing real- time applications. The main objective of real-time operating system is their quick and predictable response to events. Such systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. Real-Time Operating System18 19. A multiprogramming operating system is a system that allows more than one active user program to be stored in main memory simultaneously. Time- sharing systems are multiprogramming systems. More than one job is ready at the same time. Multiprogramming Operating System 19 20. Operating System can also be classifiedas follows Single User Systems Multi User Systems20 21. Provides a platform for only one user at a time. Theyare popularly associated with Desktop operating system which run on standalone systems where no user accounts are required. Example: DOS 21 22. Refers to computer systems that support two ormore simultaneous users. Another term for multi-user is time sharing. Example: Unix 22 23. Microsoft Windows Linux Unix Mac OS X23 24. Microsoft Windows Gamers Peoplewho must use Windows-only software forwork or school. Peopleor businesses looking for an inexpensivecomputer yet do not have the ability to use Linux. 24 25. Linux And Unix Experienced computer users looking for a good,free operating system. Businesses looking for reliable and affordablecomputing, so long as they do not need Windows-only software and have a competent IT manager. 25 26. Mac OS X Home users looking for an easy and reliablecomputing experience who are willing to pay morethan low-end PC prices. Graphic designers and photographers. Scientists. 26 27. Though it is not clear which is the best operating system, aseach does have its advantages and disadvantages, and differentpeople will be best using different ones. Microsoft Windows is acommon operating system and is a reasonable choice for mostpeople. Mac OS is second-most popular and is an excellentoperating system for those who can purchase a Mac. Linux is avery good advanced operating system available for free and isused by experienced users. 27 28. www.wikipedia.com Operating SystemConcepts 6th Edition bySilberschatz Galvin28 29. 29