Types of Operating System

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Types of operating system.

Operating system and computer hardware have a great influence on each other. To facilitate the use of hardware, OS were developed and as the trend changed in hardware, working of OS also changed and vice versa. To understand working of OS, it’s better to have a look over its evolution which divides OS into following categories.

Batch Processing System

In earlier days of computing, punched cards were used instruction and data into computer by humans. That was a very time consuming task and wasted precious CPU time. To avoid this, similar type of jobs is collected and submitted as group to computer. This concept is still used today where multiple jobs are queued and processed one by one at a specific period of time. These systems are good when results are not required immediately but cannot be used when processing is immediately required. This system is non interactive i.e. does not require user interventions during the processing. Example of batch processing system is billing systems of telephone companies where monthly data of all customer is gathered and processed at the end of month.

Time-Sharing System

In this system, unlike the batch processing system, input and output are performed from multiple terminals, which are attached to a single Computer. CPU time and memory is shared among the various users interacting from terminals. Each user process is allotted a fixed time period and CPU switches between the user processes. From this system onwards user intervention is allowed. These are also known as multi-user operating system. With development of PCs same concept is used on stand-alone computer to handle multiple processes. Here one CPU can handle more than one task concurrently. This is known as multitasking operating systems. For example, in a multitasking system a user can work on an accounting software, print a letter from word processor and play music at the same time.

Real-Time Operating System

A real time process is a process that must respond to the events within a certain time period. A real time operating system is an operating system that can run real time processes successfully. A real time operating system has well defined fixed time constraints. Process must be done within the defined constraints or the system will fail. Often used as a control device in a dedicated application such as controlling scientific experiments, industrial control systems. An example is the operating system for a flight control computer.

Multiprocessor System

A multiprocessor system uses more than one processor to enhance performance. Processes are distributed to all the processor. These are also known as parallel processing systems. An OS that is able to incorporate multiprocessor system is called as multiprocessor censor operating system.

Embedded Operating System

An embedded system is a device that contains computer logic on a chip inside it. The chip controls one or more functions of the equipment. An embedded operating system is an operating system for embedded systems. These operating systems are designed to be very compact and efficient, they do not have as much functionality as other types of operating systems provide and these may not be used by the specialized applications. Digital, Equipment’s, like T.V., micro wave and electronic traffic controller user such system.

Distributed Operating System

Distributed Operating System is a model where distributed applications are running on multiple computers linked over the network. A distributed operating system is a network operating system that supports higher levels of communication and integration of the machines on the network.

This system appeared to its users like an ordinary centralized operating system but runs on multiple, independent central processing units (CPUs).

These systems are referred as loosely coupled systems where each processor has its own local memory and processors communicate with one another through various communication lines, such as high speed buses or telephone lines. The Distributed OS involves a collection of autonomous computer systems, capable of communicating and cooperating with each other through a LAN/WAN.