CHAPTER 1 CHAPTER 2 CHAPTER 3 CHAPTER 4 CHAPTER 5 CHAPTER 6 CHAPTER 7 CHAPTER 8 CHAPTER 9 CHAPTER 10 CHAPTER 11 CHAPTER 12 CHAPTER 13 CHAPTER 14 CHAPTER 15 SYSTEM SOFTWARE FUNDAMENTAL OF OPERATING SYSTEM PROCESS MANAGEMENT THREAD MANAGEMENT CONCURRENCY CONTROL DEADLOCK MEMORY MANAGEMENT VIRTUAL MEMORY I/O HARDWARE I/O SOFTWARE SECONDARY STORADE MANAGEMENT FILE SYSTEMS PROTECTION SECURITY LINUX SYSTEM
CHAPTER 1 SYSTEM SOFTWARE
1.0 Objectives 1.1 Introduction 1.2 Operating System 1.2.1 Definition of operating system 1.2.2 Functions of Operating System 1.2.3 Operating System as User Interface 1.3 I/O System Management 1.4 Assembler 1.5 Compiler 1.6 Loader 1.7 History of Operating System 1.8 Summary 1.9 Model Question
After going through this unit, you will be able to: Describe Basic Organization of Computer Systems Define Operating system, functions, history and Evolution Define assembler, linker, loader, compiler
An operating system act as an intermediary between the user of a computer and computer hardware. The purpose of an operating system is to provide an environment in which a user can execute programs in a convenient and efficient manner. An operating system is a software that manages the computer hardware. The hardware must provide appropriate mechanisms to ensure the correct operation of the computer system and to prevent user programs from interfering with the proper operation of the system.
1.2 Operating System
1.2.1 Definition of Operating System: An Operating system is a program that controls the execution of application programs and acts as an interface between the user of a computer and the computer hardware.
A more common definition is that the operating system is the one program running at all times on the computer (usually called the kernel), with all else being applications programs. An Operating system is concerned with the allocation of resources and services, such as memory, processors, devices and information. The Operating System correspondingly includes programs to manage these resources, such as a traffic controller, a scheduler, memory management module, I/O programs, and a file system.
1.2.2 Functions of Operating System Operating system performs three functions: 1. Convenience: An OS makes a computer more convenient to use. 2. Efficiency: An OS allows the computer system resources to be used in an efficient manner. 3. Ability to Evolve: An OS should be constructed in such a way as to permit the effective development, testing and introduction of new system functions without at the same time interfering with service.
1.2.3 Operating System as User Interface Every general purpose computer consists of the hardware, operating system, system programs, application programs. The hardware consists of memory, CPU, ALU, I/O devices, peripheral device and storage device. System program consists of compilers, loaders, editors, OS etc. The application program consists of business program, database program. The fig. 1.1 shows the conceptual view of a computer system
Fig 1.1 Conceptual view of a computer system
Every computer must have an operating system to run other programs. The operating system and coordinates the use of the hardware among the various system programs and application program for a various users. It simply provides an environment within which other programs can do useful work. The operating system is a set of special programs that run on a computer system that allow it to work properly. It performs basic tasks such as recognizing input from the keyboard, keeping track of files and directories
on the disk, sending output to the display screen and controlling a peripheral devices.
OS is designed to serve two basic purposes : 1. It controls the...