Operating System: Introduction

These Operating Systems Tutorials provides the basic and intermediate and advanced concept of Operating Systems. Our Operating Systems tutorials is designed for beginners, professionals and advanced Peoples.

An Operating System acts an intermediary between the user of a Computer and the Computer Hardware. The purpose of an Operating System is to provide an environment and efficient manner.

An Operating system is software that manages computer Hardware. It also provides a basis for application programs a basis for application programs and act as intermediary between the Computer user and computer hardware. Its job is to provide user programs with a better, simpler, cleaner, model of the computer, these tasks in a wide variety of computing environments. Operating Systems are from cars and home appliances that include “Internet of Things” devices, to smart phones, Personal Computers and Enterprise Computers, and Cloud Computing environments.

Operating Systems

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The role of An Operating System in a modern Computing Environments, it is important first to understand the organization and architecture of computer hardware. This includes the CPU, memory, and I/O devices, as well as storage. A fundamental responsibility of an operating System is to allocate these resources to Programs.

Because an Operating System is large and complex, it must be created piece by piece. Each of these pieces should be a well-delineated portion of the system, with carefully defined inputs, outputs, and functions. Most reader had some experience with an operating system such as Windows, Linux, FreeBSD, or OS X, but appearances can be deceiving.

A Simple overview of the major components of a computer system as well as the functions provided by the operating system. We cover several topics to set the stage for the remainder of the text data structures used in operating systems, computing environments, and open-source and free operating systems.

What is Operating Systems:-

An Operating Systems  is the user interface program, shell, is the lowest level of user –mode software, and allows the user to start other programs, such as a web browser, email reader, or music player. These programs make heavy use of operating systems.  It runs on the bare Hardware and provides the base for all software. A simple overview of the main components at the bottom is hardware. The Hardware Consists on chips, boards, disks, a keyboard , a monitor and similar physical objects.  On the top of the hardware is the software. Most computers have two modes of operation: kernel mode and user mode. The operating system, the fundamental piece of Software runs in Kernel mode (also called Supervisor mode).

An abstract view of Operating Systems

An operating system is software which    performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

Some popular Operating Systems include Linux Operating System, Windows Operating System, VMS,OS/400, AIX, z/OS, etc.

What does an Operating system do?

1. Process Management
2. Process Synchronization
3. Memory Management
4. CPU Scheduling
5. File Management
6. Security

Operating Systems: Index

Operating System Tutorials

• Operating Systems: Introduction
• Operating Systems: Overview                                                                     
• Services of Operating Systems
• Types of Operating Systems                                                                            
• Properties of Operating Systems
• Operating-Systems Organization
• Computer- System Architecture in Operating Systems
• Operation of Operating Systems 
• Security And Protection of Operating system
• History of Operating Systems
• Open and Source Operating Systems
• Computer Hardware in Operating Systems
• Operating Systems Concepts
• System Calls
• Structure of Operating Systems
• Operating Systems Environments
• Virtualization     
• Real time systems
• Tasks in Real Time systems
• Difference between multitasking, multithreading and multiprocessing
• Types of computer memory (RAM and ROM)
• Difference between 32-bit and 64-bit operating systems
• What happens when we turn on computer?
• Boot Block
• UEFI(Unified Extensible Firmware Interface) and how is it different from BIOS

         ·           Process Management

• Process Management in OS
• Attributes of a Process
• Process States
• Process Schedulers
• Process Queues
• Times Related to Process
• CPU Scheduling
• Scheduling Algorithms
• FCFS Scheduling
• Convoy Effect in FCFS
• FCFS with overhead
• SJF Scheduling
• Burst Time Prediction
• SRTF scheduling
• Round Robin Scheduling
• RR scheduling Example
• HRRN Scheduling
• HRNN Example
• Priority Scheduling
• Non Preemptive Priority
• Preemptive Priority
• SRTF:IO bound processes

Synchronization

• Introduction
• Critical Section Problem
• Lock Variable Mechanism
• TSL Mechanism
• Priority Inversion in TSL
• Turn Variable
• Interested Variable
• Paterson Solution
• Without Busy Waiting
• Sleep and Wake
• Semaphore Introduction
• Counting Semaphore
• Problem on counting semaphore
• Binary Semaphore

Deadlocks

• Introduction
• Strategies Handling
• Deadlock Prevention
• Deadlock Avoidance
• Resource Allocation Graph
• Detection using RAG
• Detection and Recovery

Memory Management

• Introduction
• Fixed Partitioning
• Dynamic Partitioning
• Compaction
• Bit Map for Dynamic Partitioning
• Linked List for Dynamic Partitioning
• Partitioning Algorithms
• Need for Paging
• Paging with Example
• Binary Addresses
• Physical & Logical Address
• Page Table
• Mapping from page table
• Page Table Entry
• Page Table Size
• Finding Optimal Page Size
• Virtual Memory
• Look aside Buffer
• Demand Paging
• Inverted Page Table
• Page Replacement
• Numerical on LRU, FIFO
• Beladys Anamoly
• Segmentation
• Paging VS Segmentation
• Segmented Paging

File Management

• Attributes of the File
• Operations on the File
• File Access Methods
• Directory Structure
• Single level Directory
• Two level Directory
• Tree structured Directory
• Acyclic Graph Directories
• File System
• File System Structure
• Master Boot Record
• On Disk Data Structures
• In memory Data structures
• Directory Implementation
• Allocation Methods
• Contiguous Allocation
• Linked List Allocation
• File Allocation Table
• Indexed Allocation
• Linked Index Allocation
• Inode
• Free space Management
• Disk Scheduling
• FCFS Scheduling
• SSTF Scheduling
• SCAN and C-SCAN
• Look and C-Look
• Numerical on SSTF
• Numerical on Disk

More about Operating Systems

• More about Operating Systems

Prerequisites

Before learning the operating system tutorial, you must have the basic knowledge about the way in which a computer system operates.

Audience

Our operating system tutorial is designed to help beginners, professionals and advanced aspirants.