Overview of Operating Systems and Software

Operating Systems Overview

• Operating systems are complex software components that control computer systems.
• They serve as intermediaries between users and computer systems.
• Examples include Unix, MS Windows, MacOS, Linux, Sun Solaris, and DEC VMS.

Software Components

• Software components are programs that run on computers.
• These programs perform computations and manage other important tasks.
• Software components fall into two categories:
  • System software
  • Application software
• System software controls hardware components and acts as an environment for programmers creating application software.

System Software

• System software includes programs that control and monitor computer system hardware, as well as tools for programmers.
• It provides an environment for developing and executing application software.
• System software includes:
  • Utility software: Assists with system configuration, monitoring, and application software setup. Includes security software and diagnostics tools (e.g., security software, diagnostic tools, communication tools)
  • Device drivers: Allow peripheral devices to communicate with the computer.
• Types of users for system software:
  • System programmers
  • Application programmers
  • End users

Application Software

• Application software consists of programs designed to solve specific problems for users.
• These programs execute under the control of the operating system.
• Application programs are created for particular functions or goals.

Operating System Components

• User Interface: Communicates with users; includes text-based and graphical user interfaces (GUI).
• Kernel: Performs core system functions; includes
  • File manager: Manages files and directories.
  • Device drivers: Manage communication with hardware devices.
  • Memory manager: Allocates and manages memory.
  • Scheduler and dispatcher: Manages the order of tasks the CPU performs.

Functional Components of an OS

• Process manager
• Memory manager
• Resource manager
• File manager
• Device manager

Managing Processor Resources

• Multitasking: The ability to run multiple tasks simultaneously.
• Multithreading: Allows different parts of a single program to run simultaneously.
• Multiprocessing: Distributes processes across multiple processors for parallel operation.

File Manager

• Directory (or Folder): A user-created grouping of files and other directories.
• Directory Path: The sequence of directories leading to a specific file.

Managing Storage Resources

• File Directories and Folders: Organization of files in hierarchal structure. (Example given: C:\Music\Reggae\Marley One Love.mp3)

Memory Manager

• Allocates space in main memory.
• Might simulate larger available memory compared to physical memory by swapping data between RAM and storage (called virtual memory).

Boot Process

• Boot loader: A ROM program that runs on startup, transfers the OS to RAM and then jumps there to execute the system.
• Steps involved in booting include: Power on, starting boot program, power on self test, identifying peripheral devices, loading the operating system, then checking configuration.

Security

• Attacks from outside: Insecure passwords and sniffer software present an external security risk.
• Attacks from within: Unruly processes pose an internal security risk. Security measures for these problems include control of processes using privileged modes and instructions.

Explore the fundamentals of operating systems and software components in this quiz. Learn about system software and application software, as well as the role of utility software. Test your knowledge on how these systems interact and manage computer hardware.