Types of Operating system.
Before talking about types of Operating system, first talk about the OS.
Operating systems are programs that coordinate computer resources. They work as a mediator between the user and the application software, hardware.
Functions of the operating system.
1 An OS recognizing input from the uses by the medium of the keyboard, mouse, etc.
2 For multiple computing tasks that require storage (memory) in allocations is done by OS through memory management.
3 It makes the computer work properly and easily.
4 An OS maintains the security level of the system or other devices.
5 The OS helps to perform the task at a very high level in a large system or application software.
Types of Operating system in varieties.
1 Real-time operating system (RTOS):
A real-time system is a computer system capable of processing data so quickly that, the results are instantly available or typically without buffer delays.
Also, real-time OS is a time-bound system that has well defined fixed time constraint.
A real-time OS has very little user-interface capability.
There are no end-user utilities since the system will be a “Sealed box” when delivered for use.
The memory allocation in RTOS is more critical than compared to other operating systems.
Key factors in an RTOS are minimal interrupt latency and also minimal switching latency.
Some RTOS are created for special applications and others are the more general purpose.
However, an RTOS is important more for how instant or how predictable it can respond than for the amount of work it can perform in a given period of time.
Here are some examples of the real-time operating system.
|Window CE||embedded||X86, MIPS, ARM, superH|
|Simulink Real-time||Real-time testing – embedded||X86|
Some of the examples of the General-purpose operating system, such as UNIX, DOS are not real-time.
Lots of Algorithms are used in the real-time operating system. Here a few are mention.
• The fixed priority pre-emptive scheduling, which is an implementation of preemptive time slicing.
• Fixed-priority Non-preemptive scheduling.
• Fixed-priority scheduling with Deferred preemptive.
• Static time scheduling.
• Round-robin scheduling.
• Stochastic digraphs with multi-threaded graph traversal.
Types of Operating system continued.
2 Multi-access OS: This OS allows multiple users to run programs at the computer’s resources simultaneously.
A single CPU holds different terminal, each program which is using by the multiple users has necessary and separate resources required by the different user to connected to it.
Examples: UNIX, Linux, Windows etc.
3 Single-tasking operating system: In this OS only one user can perform a single task effectively at a time at a computer system.
Example: The Palm OS for the palm computers.
4 Multi-processing OS: In this OS multiple CPU is used for running a program that shares some or all of the memory of a computer system.
Examples: Linux, UNIX, Windows.
5 Multiprogramming OS: More than one program resides in main memory and is being processed apparently at the same time.
Example: Windows-like, running google chrome and Firefox browsers at the same time.
6 Batch Operating system: It is a kind of processing technique.
In this process, an OS collect the program and the data together in a batch before processing starts. In this, the OS defines a job in which a predefined sequence of commands, data, and programs as a single unit.
The jobs are entered and stored on a disk in a batch queue and then run together under the control of the OS.
A new job gets started as soon as the previous job is finished, without doing any manual intervention.
A job may wait in a batch queue for minutes or hours depending on the workload.
This created difficulty in debugging the program.
This type of OS is commonly used in today’s world, in which a user can perform multiple operations at the same time. This OS provides the market a reasonable cost and allows the users to share the computer simultaneously.
Examples: Microsoft Windows, Mac OS of Apple company.