History Of Operating System..part.1

Operating systems are the software that makes the hardware usable. Hardware

provides “raw computing power.” Operating system makes the computing power conveniently available to users, by managing the hardware carefully to achieve good performance. Operating systems can also be considered to be managers of the resources. An operating system determines which computer resources will be utilized for solving which problem and the order in which they will be used. In general, an operating system has three principal types of functions.

•  Allocation and assignment of system resources such as input/output devices, software, central processing unit, etc.
•  Scheduling: This function coordinates resources and jobs and follows certain given priority. 
• Monitoring: This function monitors and keeps track of the activities in the computer system. It maintains logs of job operation, notifies end-users or computer operators of any abnormal terminations or error conditions. This function also contains security monitoring features such as any authorized attempt to access the system as well as ensures that all the security safeguards are in place (Laudon and Laudon, 1997).

Throughout the history of computers, the operating system has continually evolved as the needs of the users and the capabilities of the computer systems have changed. As Weizer (1981) has noted, operating systems have evolved since the 1940s through a number of distinct generations, which roughly correspond to the decades. Although this observation was made in 1981, this is still roughly valid after two decades. In this paper, we shall also follow the similar approach and discuss the history of operating systems roughly along the decades.


source : Prof. Tim Bergin