9th Class Computers Science Understanding Basic Concepts of Operating System Multitasking OS

   Multitasking OS

Operating systems that allow multiple software processes to be run at the same time is called multitasking OS, such as Microsoft Windows XP and Linux. It means multitasking operating systems allow a user to do more than one thing at the same time. For example, when working on Windows operating system, you can listen to music and work on MS Word simultaneously. This is one of the best examples of multitasking OS.  

 OS as Resource Manager

Operating system works as a resource manager. It involves the following

• Process management
• Multiprogramming
• Memory Management
• Spooling  

  Process Management

In computer science process is a program execution. During program execution, a process needs various resources such as CPU time, memory space, files and I/O devices. At a particular instance of time, a computer system normally consists of a collection of processes. The process management module of an operating system involves creation and deletion of processes, scheduling of various system resources to the different processes requesting them and providing mechanism for synchronization and communication among processes. Job Scheduling is a kind of software application which provides a GUI and a single point of control for monitoring of background executions.  

 Multiprogramming

The concept of multiprogramming brings new revolution in computer's world, basically multiprogramming is a technique to execute number of programs simultaneously by one processor. In multiprogramming more than one job reside in main memory at a time. The operating system picks the job one by one and executes simultaneously in the main memory. For example, you can work MS Word, MS Excel and Power point simultaneously. Various operating systems, such as Windows XP, Mac and Linux support multiprogramming.  

 Memory

Management Memory management is one of the most important parts of the operating system. In early days, execution of computer programs was based on existing memory. The concept of virtual memory overcomes this limitation. Basically virtual memory is a technique which enables to run a big program on available memory. For example, you can run 600 MB program on 32 MB RAM. The memory management module of an operating system takes care of the allocation and deal location of memory space to the various programs in need of this resource.  

 Spooling

Simultaneous Peripheral Operations On Line (Spooling) is a process of transferring data. Program is used to buffer data for the printer and remote batch terminals. This process sends the output to the disk and printer does not interact with CPU during printing. Spooling utilities are used mainly in computer systems with multiuser/networking - environment. In networking/multi - user environments, the input and output devices are generally slow. Due to this the processing of computer is also slowed down. To control such kind of slowed down, the spooling programs are used.