Operating System Tutorial

What is Operating System Evolution of Operating System Types of Operating System Functions of Operating System What is Kernel and Types of Kernel Operating System Properties Operating System Services Components of Operating System Needs of the Operating System Linux Operating System Unix Operating System Ubuntu Operating System What is DOS Operating System Difference Between Multi-programming and Multitasking What is Thread and Types of Thread Process Management Process State What is Process Scheduler and Process Queue What is Context Switching What is CPU Scheduling Scheduling Algorithm FCFS (First-come-First-Serve) Scheduling SJF (Shortest Job First) Scheduling Round-Robin CPU Scheduling Priority Based Scheduling HRRN (Highest Response Ratio Next) Scheduling Process Synchronization Lock Variable Mechanism TSL Mechanism Turn Variable Mechanism Interested Variable Mechanism What is Producer-Consumer Problem What is Semaphore in Operating System Monitors in Operating System What is Deadlock Deadlock Avoidance Strategies for Handling Deadlock Deadlock Prevention Deadlock Detection and Recovery Resource Allocation Graph Banker’s Algorithm in Operating System Fixed Partitioning and Dynamic Partitioning Partitioning Algorithms What is Paging and Segmentation What is Demand Paging What is Virtual Memory Disk Scheduling Algorithms FCFS and SSTF Disk Scheduling Algorithm SCAN and C-SCAN Disk Scheduling Algorithm Look and C-Look Disk Scheduling Algorithm File in Operating System File Access Methods in Operating System File Allocation Method Directory Structure in Operating System Difference between C-LOOK and C-SCAN Difference between Rotational Latency and Disk Assess Time Trap vs Interrupt How to implement Monitors using Semaphores N-Step-SCAN Disk Scheduling Why is it critical for the Scheduler to distinguish between I/O-bound and CPU-bound programs Difference between C-SCAN and SSTF Difference between SCAN and FCFS Difference between Seek Time and Disk Access Time Difference between SSTF and LOOK

Operating System Tutorial

What is an Operating System?

An Operating System is a System Software that handles the resources of a computer such as computer hardware and software and offers frequent services to the computer programs. In other words, an operating system is defined as a software that creates an interface between the user and computer hardware.

Operating System Tutorial

In the computer system, to run any program, at least one operating system is a must. An application such as MS word, chrome, games, etc. requires an environment so that the application can run and perform its functions. Through the operating system, communication is done easily with the computer without knowing computer languages. Without the operating system, it is not possible to use any computer or mobile device.

Operating System

The operating system is useful to monitor and handle the execution of other programs that are present in the computer, consisting of applications and system software. The main objective of the operating system is to offer an environment so that the user can appropriately execute a program.                                                                       

Objective of the Operating System

The objectives of the operating system are:

  1. The operating system offers users an appropriate interface to use the computer system.
  2. It helps us to hide the information related to the hardware resources from the users.
  3. The operating system provides the sharing of resources among users and programs in an efficient way.
  4. The operating system helps us to manage the computer system resources.
  5. The operating system offers convenient and impartial sharing of resources between the users and programs.

Features of Operating System

Objective of the Operating System
  1. Memory management: - Operating system keep track of the primary memory, means it keeps track of what part of memory is used, what part is not in use, and also helps to allocate the memory when a process requests it.
  2. Processor management: - Processor management means allocating processors to the process when the process needs and also deallocates the processor when the process does not require the processor.
  3. Device management: - The operating system also maintains the track of all the devices, which means an operating system decides which process should get the device, when and for how much time.
  4. File management: - The operating system provides the facility of file management.
  5. Security: - The operating system prevents programs and data from unauthorized access by using passwords and some other techniques.
  6. Job accounting: - It also keeps track of resources and time used by different jobs.
  7. Control over system performance: - It also helps to keep the recovery delays among the request for a service and from the system.
  8. Error-detecting Aids: - The operating system also provides the facility of error detection by the production of dumps, traces, error messages, and by using different debugging and error detecting techniques.

History of the Operating System

  1. The first operating system was developed in the late 1950s to manage the tape storage.
  2. In 1950, IBM 701-the general motors research lab developed the first operating system.
  3. In the 1960s, disks were used in the operating system, and the primary version of the Unix operating system was developed.
  4. Microsoft’s first developed Operating System was DOS. It was developed in 1981 by purchasing a Seattle company 86-DOS software.
  5. In 1985, the time when the GUI was developed and combined with MS-DOS, the current popular window OS first came into being.

Basic elements of the Operating System

The basic elements of the Operating System are:

  1. Main Memory
  2. Processor
  3. System bus
  4. I/O modules

Main Memory: - Main memory is also called Primary memory or Volatile memory. Main memory stores data and programs. The main memory is called volatile memory because when the system is turned off, then the content of the memory is erased automatically, or content is lost.

Processor: - A processor is defined as an integrated electronic circuit which performs the job of calculations in the computer. It performs input/output(I/O), arithmetical logical operations, and basic instructions that are passed from an operating system. The task of the processor is to control the processes in the computer and also perform data processing functions. If there is only one processor, then it is called a central processing unit (CPU), which you all know.

A processor may consist Arithmetical logical unit and control unit, which measures the capability in terms of the following.

  • Maximum number of bits/instructions.
  • Relative clock speed.
  • Capability to process instructions at a given time

System bus: - System bus is the element of the operating system which is responsible for communication between the processors, I/O modules, and main memory.

I/O Modules: - The task of I/O modules is to move the data within the computer to its peripheral external environment. The external environment consists of various types of devices like secondary memory like pen drives, CDs, etc. communications equipment like (LAN cable), terminals, etc.

Operating System Index