Lesson 1 - Operating System Concepts

Operating system

A collection of software that manages the computer hardware resources and provides common services for computer programs.

Resource manager view and Extended machine view

What is the two viewpoints of OS?

Resource manager view

The operating systems’ job is to manage the different parts of the system efficiently.

Extended machine view

The job of the system is to provide the users with abstractions that are more convenient to use than the actual machine. These include processes, address spaces, and files.

Memory management

Refers to the management of primary memory or main memory.

Main memory

A large array of words or bytes where each word or byte has its own address. It provides a fast storage that can be accessed directly by the CPU.

Memory management

Keeps tracks of primary memory, i.e., what part of it are in use by whom, what part are not in use.

Memory management

In multiprogramming, the OS decides which process will get memory when and how much.

Memory management

Allocates the memory when a process requests it to do so.

Memory management

De-allocates the memory when a process no longer needs it or has been terminated.

Processor scheduling

In multiprogramming environment, the OS decides which process gets the processor when and for how much time.

Processor management

Allocates the processor (CPU) to a process.

Processor management

De-allocates processor when a process is no longer required.

Traffic controller

Keeps tracks of processor and status of process.

Device management

An Operating System manages device communication via their respective drivers.

I/O controller

Keeps tracks of all devices.

Device management

Decides which process gets the device when and for how much time. Allocates the device in the efficient way. De-allocates devices.

File management

A file system is normally organized into directories for easy navigation and usage.

File system

Keeps track of information, location, uses, status etc. The collective facilities are often known as a what?

File management

Decides who gets the resources. Allocates the resources. De-allocates the resources.

Security

By means of password and similar other techniques, it prevents unauthorized access to programs and data.

Control over system performance

Recording delays between request for a service and response from the system.

Job accounting

Keeping track of time and resources used by various jobs and users.

Error detecting aids

Production of dumps, traces, error messages, and other debugging and error detecting aids.

Coordination between other software and users

Coordination and assignment of compilers, interpreters, assemblers and other software to the various users of the computer systems.

Primary Goal

To provide a user-friendly and convenient environment.

Secondary Goal

Efficiency of use.

Batch operating system

This type of operating system does not interact with the computer directly. There is an operator which takes similar jobs having same requirement and groups them.

Time sharing operating system

Each task is given some time to execute, so that all the tasks work smoothly. Each user gets time of CPU as they use single system.

Multitasking Systems

Other term for Time sharing operating system

Quantum

The time that each task gets to execute is called?

Distributed operating system

Use multiple central processors to serve multiple real-time applications and multiple users. Data processing jobs are distributed among the processors accordingly.

Loosely coupled systems

Other term for Distributed operating system

Network operating system

Runs on a server and provides the server the capability to manage data, users, groups, security, applications, and other networking functions.

Real time operating system

A data processing system in which the time interval required to process and respond to inputs is so small that it controls the environment.

Response time

The time taken by the system to respond to an input and display of required updated information is termed as?

Hard real time systems

Guarantee that critical tasks complete on time. In this type of real-time system, secondary storage is limited or missing, and the data is stored in ROM. In these systems, virtual memory is almost never found.

Soft real time systems

This real-time system is less restrictive. A critical real-time task gets priority over other tasks and retains the priority until it completes.

Payroll system, bank statements

State the examples of Batch based Operating Systems

Multics, Unix

State the Examples of Time-Sharing OSs

LOCUS

State the Examples of Distributed Operating Systems

Microsoft Windows Server 2003 and 2008, UNIX, Linux

State the Examples of network operating systems

1945-1955

What was the period of the First Generation?

Vacuum tubes and plugboards

What technology was used in the First Generation?

1955-1965

What was the period of the Second Generation?

Transistors and batch systems

What technology characterized the Second Generation?

GMOS

What was the first operating system introduced in the early 1950s?

General Motors

Who created GMOS?

IBM 701

What machine was GMOS created for?

Single stream batch systems

What were operating systems in the 1950s called?

Mainframes

What were the new machines of the Second Generation called?

Fortran Monitor System

What does FMS stand for?

IBM's operating system for the 7094

What was IBSYS?

1965-1980

What was the period of the Third Generation?

Integrated Circuits

What major technology characterized the Third Generation?

Multiprogramming

What major operating system development occurred in the Third Generation?

Minicomputers

What type of computers experienced phenomenal growth during the Third Generation?

DEC PDP 1 (1961)

What computer helped start the growth of minicomputers?

1980-Present

What is the period of the Fourth Generation?

Personal computers

What is the main focus of the Fourth Generation?

Microsoft and Apple

What major companies contributed to personal computing?

Bill Gates and Paul Allen

Who founded Microsoft?

MS-DOS

What operating system did Microsoft introduce in 1981?

Windows 95, 98, XP, 7, 8, 10

Name some versions of Windows mentioned in the lesson.

Steve Jobs

Who was a co-founder of Apple?

Apple Macintosh

What computer did Apple create?

1990-present

What is the period of the Fifth Generation according to the lesson?

Ultra Large Scale Integration

What’s the development of VLSI technology in the Fifth Generation?