Chapter 3 - Overview of operating systems. This chapter deals with the fundamental principles of an operating system; it is a key chapter in the book. It discusses the nature of computations in different kinds of computing environments and features of operating systems used in these environments, and follows up this discussion with the notions of efficiency, system performance, and user service. | Chapter 3 Overview of Operating Systems Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction Computing Environments and Nature of Computations Classes of Operating Systems Efficiency, System Performance, and User Service Batch Processing Systems 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction (continued) Multiprogramming Systems Time-Sharing Systems Real-Time Operating Systems Distributed Operating Systems Modern Operating Systems 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Computing Environments and Nature of Computations A computing environment consists of a computer system, its interfaces with other systems, and the services provided by its operating system to its users and their programs Evolution: Noninteractive Computing Environments Interactive Computing Environments Real-Time, Distributed, and Embedded . | Chapter 3 Overview of Operating Systems Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction Computing Environments and Nature of Computations Classes of Operating Systems Efficiency, System Performance, and User Service Batch Processing Systems 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Introduction (continued) Multiprogramming Systems Time-Sharing Systems Real-Time Operating Systems Distributed Operating Systems Modern Operating Systems 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Computing Environments and Nature of Computations A computing environment consists of a computer system, its interfaces with other systems, and the services provided by its operating system to its users and their programs Evolution: Noninteractive Computing Environments Interactive Computing Environments Real-Time, Distributed, and Embedded Environments Modern Computing Environments 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Computing Environments and Nature of Computations (continued) Noninteractive Computing Environments OS focuses on efficient use of resources Computations in form of program or job Interactive Computing Environments OS focuses on reducing average amount of time required to implement an interaction between a user and his computation Execution of a program is called a process 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Computing Environments and Nature of Computations (continued) 3. Operating Systems, by Dhananjay Dhamdhere Copyright © 2008 Operating Systems, by Dhananjay Dhamdhere Computing Environments and Nature of Computations (continued) Real-Time, Distributed, and Embedded Environments A real-time computation has specific time constraints OS ensures computations .