Chapter-1 Computer is an advanced electronic device that takes raw data as an input from the user and processes it under the control of a set of instructions.

Slides:



Advertisements
Similar presentations
CS 345 Computer System Overview
Advertisements

Chapter 1: Introduction
UNIX Chapter 01 Overview of Operating Systems Mr. Mohammad A. Smirat.
1/16/2008CSCI 315 Operating Systems Design1 Introduction Notice: The slides for this lecture have been largely based on those accompanying the textbook.
Copyright Arshi Khan1 System Programming Instructor Arshi Khan.
Operating Systems.
Systems Software Operating Systems.
Week 6 Operating Systems.
Computer Organization ANGELITO I. CUNANAN JR. 1. What is Computer?  An electronic device used for storing and processing data.  It is a machine that.
Chapter 1. Introduction What is an Operating System? Mainframe Systems
Operating Systems CS3502 Fall 2014 Dr. Jose M. Garrido
 What is OS? What is OS?  What OS does? What OS does?  Structure of Operating System: Structure of Operating System:  Evolution of OS Evolution of.
Operating Systems.
OS provide a user-friendly environment and manage resources of the computer system. Operating systems manage: –Processes –Memory –Storage –I/O subsystem.
المحاضرة الاولى Operating Systems. The general objectives of this decision explain the concepts and the importance of operating systems and development.
1.1 Operating System Concepts Introduction What is an Operating System? Mainframe Systems Desktop Systems Multiprocessor Systems Distributed Systems Clustered.
Systems Software Operating Systems. What is software? Software is the term that we use for all the programs and data that we use with a computer system.
Silberschatz and Galvin  Operating System Concepts Module 1: Introduction What is an operating system? Simple Batch Systems Multiprogramming.
Chapter 1 Basic Concepts of Operating Systems Introduction Software A program is a sequence of instructions that enables the computer to carry.
Operating Systems.
1.1 Sandeep TayalCSE Department MAIT 1: Introduction What is an operating system? Simple Batch Systems Multiprogramming Batched Systems Time-Sharing Systems.
Operating Systems (Credit to: Rick Graziani of Cabrillo College)
Chapter 1: Introduction What is an Operating System? Mainframe Systems Desktop Systems Multiprocessor Systems Distributed Systems Clustered System Real.
Chapter 1: Introduction What is an Operating System? Mainframe Systems Desktop Systems Multiprocessor Systems Distributed Systems Clustered System Real.
INTRODUCTION TO COMPUTERS. A computer system is an electronic device used to input data, process data, store data for later use and produce output in.
1 OPERATING SYSTEMS. 2 CONTENTS 1.What is an Operating System? 2.OS Functions 3.OS Services 4.Structure of OS 5.Evolution of OS.
Introduction to Operating Systems Concepts
Introduction to Computing Systems
OPERATING SYSTEM CONCEPT AND PRACTISE
Applied Operating System Concepts
Introduction to comp. and prog. CS 101 G 964
Operating Systems & System Software
Chapter 1: Introduction
Chapter 1: Introduction
Operating Systems Lecture 2.
Nature & Types of Software
Operating System Review
2. OPERATING SYSTEM 2.1 Operating System Function
Operating System.
Computer Software.
Chapter 1: Introduction
Chapter 1: Introduction
Chapter 1: Introduction
Operating System Structure
Introduction to Operating System (OS)
Chapter 1: Introduction
Chapter 1: Introduction
Chapter 1: Introduction
Chapter 1: Introduction
Operating System Review
חוברת שקפים להרצאות של ד"ר יאיר ויסמן מבוססת על אתר האינטרנט:
Chapter 2: System Structures
Operating Systems.
Operating System Concepts
Chapter 1: Introduction
Operating Systems Lecture 2.
Lecture Topics: 11/1 General Operating System Concepts Processes
Language Processors Application Domain – ideas concerning the behavior of a software. Execution Domain – Ideas implemented in Computer System. Semantic.
Introduction to Operating Systems
Chapter 1: Introduction
Chapter 1: Introduction
Chapter 1: Introduction
Data Communications and Computer Networks
Software - Operating Systems
Chapter 1: Introduction
Introduction to Operating Systems
Chapter 1: Introduction
Operating System Concepts
Chapter 1: Introduction
Fundamentals of Computer Hardware & software
Presentation transcript:

Chapter-1 Computer is an advanced electronic device that takes raw data as an input from the user and processes it under the control of a set of instructions (called program), produces a result (output), and saves it for future use. This tutorial explains the foundational concepts of computer hardware, software, operating systems, peripherals, etc. along with how to get the most value and impact from computer technology. A computer is a programmable machine designed to perform arithmetic and logical operations automatically and sequentially on the input given by the user and gives the desired output after processing. Computer components are divided into two major categories namely hardware and software. Hardware is the machine itself and its connected devices such as monitor, keyboard, mouse etc. Software are the set of programs that make use of hardware for performing various functions.

Functional Units of Computer

Computer Software Computer software is the set of programs that makes the hardware perform a set of tasks in particular order. Hardware and software are complimentary to each other. Both have to work together to produce meaningful results. Computer software is classified into two broad categories; system software and application software. 1.5.1 System Software: System software consists of a group of programs that control the operations of a computer equipment including functions like managing memory, managing peripherals, loading, storing, and is an interface between the application programs and the computer. MS DOS (Microsoft’s Disk Operating System), UNIX are examples of system software. 1.5.2 Application software: Software that can perform a specific task for the user, such as word processing, accounting, budgeting or payroll, fall under the category of application software. Word processors, spreadsheets, database management systems are all examples of general purpose application software.

Computer Language Computer language or programming language is a coded syntax used by computer programmers to communicate with a computer. Computer language establishes a flow of communication between software programs. The language enables a computer user to dictate what commands the computer must perform to process data. These languages can be classified into following categories. 1. Machine language 2. Assembly language 3. High level language

Operating System An operating system is a software component of a computer system that is responsible for the management of various activities of the computer and the sharing of computer resources. It hosts several applications that run on a computer and handles the operations of computer hardware. Users and application programs access the services offered by the operating systems, by means of system calls and application programming interfaces. Users interact with a computer operating system through Command Line Interfaces (CLIs) or Graphical User Interfaces known as GUIs. In short, an operating system enables user interaction with computer systems by acting as an interface between users or application programs and the computer hardware. Some of the common operating systems are LINUX, Windows, etc.

Important functions of an operating System. Memory Management Processor Management Device Management File Management Security Control over system performance Job accounting Error detecting aids Coordination between other software and users

Batch System Batch Systems • Introduction of tape drives allow batching of jobs: – programmers put jobs on cards as before. – all cards read onto a tape. – operator carries input tape to computer. – results written to output tape. – output tape taken to printer. • Computer now has a resident monitor : – initially control is in monitor. – monitor reads job and transfer control. – at end of job, control transfers back to monitor. • Even better: spooling systems. – use interrupt driven I/O. – use magnetic disk to cache input tape. – fire operator. • Monitor now schedules jobs. . .

Multi-Programming Use memory to cache jobs from disk ) more than one job active simultaneously. • Two stage scheduling: 1. select jobs to load: job scheduling. 2. select resident job to run: CPU scheduling. • Users want more interaction ) time-sharing: • e.g. CTSS, TSO, Unix, VMS, Windows NT. . .

Current OS Single user systems: cheap and cheerful. – personal computers. – no other users ) ignore protection. – e.g. DOS, Windows, Win 95/98, . . . • RT Systems: power is nothing without control. – hard-real time: nuclear reactor safety monitor. – soft-real time: mp3 player. • Parallel Processing: the need for speed. – SMP: 2–8 processors in a box. – MIMD: super-computing. • Distributed computing: global processing? – Java: the network is the computer. – Clustering: the network is the bus. – CORBA: the computer is the network. – .NET: the network is an enabling framework. . .

Monolithic Operating Systems Oldest kind of OS structure (“modern” examples are DOS, original MacOS) • Problem: applications can e.g. – trash OS software. – trash another application. – hoard CPU time. – abuse I/O devices. – etc. . . • No good for fault containment (or multi-user). • Need a better solution. . .

Dual-Mode Operation Want to stop buggy (or malicious) program from doing bad things. Provide hardware support to distinguish between (at least) two different modes of operation: 1. User Mode : when executing on behalf of a user (i.e. application programs). 2. Kernel Mode : when executing on behalf of the operating system. • Hardware contains a mode-bit, e.g. 0 means kernel, 1 means user. • Make certain machine instructions only possible in kernel mode. . .

Operating System Functions Regardless of structure, OS needs to securely multiplex resources: 1. protect applications from each other, yet 2. share physical resources between them. • Also usually want to abstract away from grungy harware, i.e. OS provides a virtual machine: – share CPU (in time) and provide each app with a virtual processor, – allocate and protect memory, and provide applications with their own virtual address space, – present a set of (relatively) hardware independent virtual devices, – divide up storage space by using filing systems, and – do all this within the context of a security framework. • Remainder of this part of the course will look at each of the above areas in turn. . .

MS-WORD 2000