Posts tagged Operating System

Introduction to multiprogramming

In the early days of computer science, a computer could run only one program at a time. Punch card instructions or instructions given with various electronic switches were considered to execute a given set of instructions, one after another. With the development of technology, computers and computer science was even introduced to general public. Interactive operating systems and easy to understand application software were necessary to make computer easy to use. However, this was not possible with the limitation of only executing single program at a time. Interactive, user-friendly operating systems and such applications required to run interdependently. So that multiprogramming concept was introduced. With multiprogramming it was possible to run multiple programs at a time in a single computer. Today, most of the general computers use multiprogramming and most of the operating systems and applications software are designed to run on such systems.

Why do we need CPU scheduling?

Though, it is possible to run multiple programs simultaneously using multiprogramming, CPU can only execute single instruction at a time. Because of this limit, only a single process or an instance of software can get the control of CPU for its execution. Instructions of this process will be continuously executed by the CPU blocking other processes from being executed. This problem will in turn hide advantages of multiprogramming concept. More >