Operating Systems - Lecture 1

Introduction to Operating Systems

Operating System

A program that controls the execution of application programs and acts as an interface between the user of a computer and the computer hardware.

Operating System

The one program running at all times on the computer, with all else being application programs.

Kernel

The most important part of the operating system. It is the primary interface between the hardware and the processes of a computer.

Hardware
Application Programs
Operating System
Users

Components of a computer system

Hardware

The central processing unit (CPU), the memory, and the I/O devices provides the basic computing resources for the system

Application Programs

Word processors, compilers, web browsers define the ways in which these resources are used to solve users’ computing problems

Operating System

Controls the hardware and coordinates its use among the various application programs for the various users

Users

Users of a computer system

Device driver

Typically, operating systems have a __________ for each device controller.

Device driver

This understands the device controller and provides the rest of the operating system with a uniform interface to the device.

Main Memory

General-purpose computers run most of their programs from rewritable memory, called ________.

Main Memory

Commonly is implemented in a semiconductor technology called DRAM (Dynamic Random-Access Memory).

Load

This instruction moves a byte or word from main memory to an internal register within the CPU

Store

This instruction moves the content of a register to main memory.

Resource manager

An Operating system is a ____________

Process Management
Memory Management
File-System Management
Mass-Storage Management
Cache Management
I/O System Management

Resource Management in OS

Resources; CPU Time, Memory, Files, I/O devices

A process needs certain ______ – it includes _____, _____, _____, and ______ to accomplish its task.

Initialization data

In addition to the physical and logical resources that a process obtains when it is created, various _____ (input) may be passed along.

Passive entity; Active entity

A program is a ______, like the contents of a file stored on disk,

whereas a process is an _____.

Process

A _____ is the unit of work in a system

System

A ______ consists of collection of processes, some of which are operating-system processes and the rest of which are user processes.

Central to the operation of a modern computer system

Main Memory is __________.

Quickly accessible data

Main Memory is a repository of ________ shared by the CPU and I/O devices

Memory management

To improve both the utilization of the CPU and the speed of the computer’s response to its users, general-purpose computers must keep several programs in memory, creating a need for ________.

File Management

______ is one of the most visible components of an operating system

Secondary storage; Tertiary storage

In file management, physical media such as _______ is the most common, but _____ is also possible.

File

Is a collection of related information defined by its creator

HDDs and NVM devices

Most modern computer systems use ________ as the principal on-line storage media for both programs and data.

Efficiently

Since secondary storage is used frequently and extensively, it must be used ______

Caching

It is an important principle of computer systems. In _____, information is normally kept in some storage system (such as main memory)

Cache

As it is used, it is copied into a faster storage system on a temporary basis.

Cache management

Because caches have limited size, _______ is an important design problem.

Hide the peculiarities

One of the purposes of an operating system is to ______ of specific hardware devices from the user.

I/O subsystem

The peculiarities of I/O devices are hidden from the bulk of the operating system itself by the ________

Batch Operating System

This type of operating system does not interact with the computer directly.

Operator

An ______ is present which takes similar jobs having the same requirement and groups them into batches

Multiprogramming Operating Systems

Can be illustrated as more than one program is present in the main memory and any of them can be kept in execution

Multiprocessing Operating System

Is a type of operating system in which more than one CPU is used for the execution of resources.

Multitasking Operating System

Is simply a multiprogramming operating system with having facility of a Round-Robin Scheduling Algorithm.

Multitasking Operating System

It can run multiple programs simultaneously.

Time-Sharing Operating Systems

Each task is given some time to execute so that all the tasks work smoothly

Distributed Operating System

it use many central processors to serve multiple real-time applications and users.

Network Operating System

These systems run on a server and provide the capability to manage data, users, groups, security, applications, and other networking functions.

Network Operating System; Shared access

A type of operating systems which allow _____ to files, printers, security, applications, and other networking functions over a small private network.

Real-Time Operating System

These types of OS serve real-time systems.

Real-time systems

______ are used when there are time requirements that are very strict like missile systems, air traffic control systems, robots, etc.

Batch Operating System
Multiprogramming Operating System
Multiprocessing Operating System
Multitasking Operating System
Time-Sharing Operating System
Distributed Operating System
Network Operating System
Real-Time Operating System

Types of Operating Systems