Lecture 1 introduction to Operating System
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The document provides an introduction to operating systems. It defines an operating system as a program that acts as an intermediary between the user and computer hardware, executing user programs, making the computer convenient to use, and using hardware efficiently. It describes the four main components of a computer system as hardware, operating system, application programs, and users. It also explains that the operating system is a resource allocator and control program that manages resources and controls program execution to prevent errors.
Lecture 1 introduction to Operating System
- 1. INTRODUCTION TO OPERATING SYSTEMS Amitava Nag Assistant Professor and Head Dept. of IT Academy of Technology [email protected]
- 2. Computer System with Operating System Software Hardware Operating System
- 3. Computer System with Operating System
- 4. What is an Operating System? • A program that acts as an intermediary between a user of a computer and the computer hardware • Operating system goals: – Execute user programs and make solving user problems easier – Make the computer system convenient to use – Use the computer hardware in an efficient manner
- 5. Four Components of a Computer System
- 6. Computer System Structure • Computer system can be divided into four components – Hardware – provides basic computing resources • CPU, memory, I/O devices – Operating system • Controls and coordinates use of hardware among various applications and users – Application programs – define the ways in which the system resources are used to solve the computing problems of the users • Word processors, compilers, web browsers, database systems, video games – Users • People, machines, other computers
- 7. Operating System Definition • OS is a resource allocator – Manages all resources – Decides between conflicting requests for efficient and fair resource use • OS is a control program – Controls execution of programs to prevent errors and improper use of the computer
- 8. Computer Startup • bootstrap program is loaded at power-up or reboot – Typically stored in ROM or EPROM, generally known as firmware – Initializes all aspects of system – Loads operating system kernel and starts execution
- 9. Start-up process The computer start-up process can be divided into three basic steps: Power On Self Test, BIOS, and Booting (or Bootstrap).
- 10. Computer System Organization • Computer-system operation – One or more CPUs, device controllers connect through common bus providing access to shared memory – Concurrent execution of CPUs and devices competing for memory cycles
- 12. Functions of Operating system Allocates Resources Monitors Activities Manages Disks & Files