Chapter 3: Operating System (OS). IT and Computer Science

Operating System OS

1. Course: CSC 1101 Information Technology and Computer Science Semester: June 2024 Lecturer: Ms Jayashiry Morgan

2. Chapter 3: Operating System

3. Learning Outcomes By the end of this session, students should be able to: Define an operating system and utility program and explain their key functions. Identify the different types of operating systems and their characteristics. Describe memory management, virtual memory, and the distinctions between application software and programs, including various types of applications.

4. Definition of Operating System A program that acts as an intermediary between a user of a computer and the computer hardware. An operating System is a collection of system programs that together control the operations of a computer system. Some examples of operating systems are UNIX, Mach, MS-DOS, MS-Windows, Windows/NT, Chicago, OS/2, MacOS, VMS, MVS, and VM.

5. Functions of Operating System Process Management Memory Management File System Management Device Management Security and Access Control User Interface

6. Functions of Operating System Process Management The OS manages processes, including the execution, creation, and termination of processes. It allocates CPU time and resources to processes and ensures smooth execution.

7. Functions of Operating System Memory Management The OS manages the computer's memory, including RAM and cache. It allocates memory to processes, manages swapping between memory and storage, and handles virtual memory.

8. Functions of Operating System File System Management The OS manages files and directories on storage devices. It provides a structure for storing, organizing, and accessing data.

9. Functions of Operating System Device Management The OS manages hardware devices, such as printers, disk drives, and network interfaces. It provides drivers and handles communication between hardware and software.

10. Functions of Operating System Security and Access Control The OS ensures system security by controlling access to resources and data. It enforces user authentication, authorization, and data encryption.

11. Functions of Operating System User Interface The OS provides a user interface, such as command-line interfaces (CLI) or graphical user interfaces (GUI), to interact with the system.

12. Utility Program Utility programs are software tools that perform maintenance tasks, help in managing the computer system, and optimize its performance. They are often bundled with the operating system or available as standalone applications.

13. Functions of Utility Programs File management: Tools for file copying, renaming, moving, and deleting. Disk Management : Tools for disk defragmentation, cleanup, and partitioning. System Monitoring : Tools to monitor system performance, CPU usage, and memory usage. Backup and Recovery : Tools for data backup and recovery. Security Utilities : Antivirus, anti-malware, and firewall programs.

14. Types of Operating System Batch Operating System Time-sharing Operating System Distributed Operating System Network Operating System Real-Time Operating System Embedded Operating System Mobile Operating System Desktop Operating System

15. Types of Operating System Batch Operating System Executes batches of jobs without user interaction. Example: IBM OS/360, early version of UNIX

16. Types of Operating System Time-sharing Operating System Allows multiple users to use the system simultaneously by rapidly switching between users. Examples: UNIX, Multics.

17. Types of Operating System Distributed Operating System Manages a group of independent computers and makes them appear as a single coherent system. Example: Amoeba, Plan 9

18. Types of Operating System Network Operating System Provides services to computers connected to a network, enabling resource sharing and communication. Examples: Novell NetWare, Windows Server

19. Types of Operating System Real-Time Operating System (RTOS) Provides immediate processing and responses to input. Used in systems that require precise timing and reliability. Examples: VxWorks, RTLinux

20. Types of Operating System Embedded Operating System Designed for embedded systems, running on devices with limited resources. Examples: Embedded Linux, QNX .

21. Types of Operating System Mobile Operating System Designed for mobile devices such as smartphones and tablets. Examples: Android, iOS.

22. Types of Operating System Desktop Operating System Designed for personal computers, providing a user-friendly interface and extensive application support. Examples: Windows, macOS, Linux distributions.

23. Memory Management and Virtual Memory

24. Memory Management Memory management is the function of an operating system that handles the allocation and deallocation of memory spaces. It ensures efficient memory usage and system stability.

25. Functions of Memory Management Allocation: Assigns memory to processes when they need it. Deallocation: Frees memory when it is no longer needed by processes. Tracking: Keeps track of which parts of memory are in use and by which processes. Protection: Ensures that processes do not interfere with each other’s memory spaces.

26. Virtual Memory Virtual memory is a memory management technique that gives an application the impression it has contiguous working memory while in reality, it may be fragmented and span across RAM and disk storage.

27. How Virtual Memory Works? Paging: Divides memory into fixed-size pages. The OS swaps pages between RAM and disk storage as needed. Segmentation: Divides memory into variable-sized segments based on the logical divisions of a program

28. Benefits of Virtual Memory Increased Memory Capacity: Allows programs to use more memory than physically available. Isolation: Provides process isolation, improving security and stability. Efficient Memory Utilization: Allows better utilization of available memory resources.

29. Application Software vs Programs

30. Application Software Application software refers to programs designed to perform specific tasks for users. They are built to help users complete various tasks such as word processing, web browsing, or playing games. Examples: Microsoft Office Suite (Word, Excel, PowerPoint) Web Browsers (Google Chrome, Mozilla Firefox) Media Players (VLC, Windows Media Player)

31. Programs Programs are sets of instructions that tell the computer what to do. They include both system software (like operating systems) and application software.

32. Difference? Application Software: Designed for end-users to perform specific tasks. Programs: Can refer to any set of instructions, including both system software and application software.

33. Types of Applications Productivity Applications: Help users perform tasks efficiently. Examples: Microsoft Office, Google Workspace. Communication Applications: Facilitate communication between users. Examples: Email clients (Outlook), Messaging apps (Slack, WhatsApp). Multimedia Applications: Allow users to create, edit, and play multimedia content. Examples: Adobe Photoshop, VLC Media Player.

34. Types of Applications Educational Applications: Provide educational content and tools for learning. Examples: Duolingo, Khan Academy . Web Browser: Enables users to access and interact with content on the internet. Examples: Google Chrome, Mozilla Firefox.

35. Scan the QR code below

36. We will have short quiz now. Scan the QR code below:

37. Class Activity: Understanding Operating Systems Choose your pair. Should not be same as last week. Each group will be given a scenario. Each group will research their assigned scenario, focusing on the operating system and utility programs. Discuss within the group to identify two best options for the OS and necessary utilities. Each group presents their findings to the class, explaining their choices and justifications. Use the whiteboard to brainstorm.

38. Group 1: Small Business Setup Group 1 needs to set up a computer system for a small business. They need an operating system that can efficiently handle network services, provide security, and support business applications. Tasks Research and suggest the best operating system for this scenario . List the utility programs needed for backup, antivirus, and disk management . Justify why the chosen OS and utilities are the best fit for the business environment .

39. Group 2: Real-Time Application Development Group 2 needs to develop a real-time application for a medical device. The operating system should provide immediate processing and high reliability. Tasks Research and suggest the best real-time operating system for this scenario . Identify utility programs that can assist in system monitoring, debugging, and security. Justify why the chosen OS and utilities are the best fit for the real-time application development.

40. Group 3: Multimedia Content Creation Group 3 needs to set up a workstation for multimedia content creation, requiring an operating system that supports high performance, graphical processing, and multimedia applications. Tasks Research and suggest the best operating system for multimedia content creation. Identify utility programs that can optimize performance, manage files, and enhance security. Justify why the chosen OS and utilities are the best fit for multimedia content creation.