The purpose of an operating system

What is an operating system ?An operating system or OS is a series of programmes what manage the computers hardware resources. Also it provides services for application software. Many devices use operating such as Windows 7, Game consoles and mobile phones such as smart phones.

Where might you find an operating system?

Operating systems are found everywhere in our day to day lives without us even knowing. We also use them on a day to day basis such as :

Computers

Game consoles ( Xbox 360, PS3, Nintendo Wii )

Mobile phones

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Cars

What are the main functions of an operating system?

The main functions of an operating system are to control the main hardware elements in the computer.

The five main features of an operating system:

Processor management Memory management Device management Storage management User interface

Processor management

The managing processor comes down to two related issues. Ensuring that each process and application receives enough of the processor's time to function properly. Using as many processor cycles as possible for real work. The processor can only do one thing at a time so the operating system is in charge for sending the task to the processor.

Memory management

Memory management is the act of managing computer memory. In its simpler forms, this involves providing ways to allocate portions of memory to programs at their request, and freeing it for reuse when no longer needed. The management of main memory is critical to the computer system.

Device management

The path between the operating system and almost all hardware not on the computer's motherboard goes through a special program called a driver. The drivers job is to be the translator between the electrical signals of the hardware subsystems and the high-level programming languages of the operating system and application programs.

Storage management

When an operating system manages the computer's memory there are two broad tasks to be accomplished:

Each process must have enough memory in which to execute, and it can neither run into the memory space of another process nor be run into by another process.  

The different types of memory in the system must be used properly so that each process can run most effectively.

User interface

User interface design is the design of computers, mobile and websites with the focus point on the user's experience and interaction to the interface. The point of user interface design is to make the user's interaction as simple and efficient as possible and something what appeals to the user.

What role does the OS play in managing the processor?

The OS manage the execution of processes so that you believe lots of things are happening. In order to give the appearance of lots 0f the things happening at the same time the OS has to switch between different processes.

What is a device driver?

A device driver or software driver is a computer programme which convert the messages from the OS into messages that the hardware device can understand. A device driver simplifies programming by acting as translator between a hardware device and the applications or operating systems that use it.

How does a buffer work?

A buffer is a region of a physical memory storage used to temporally hold data. The purpose of most buffers is to act as a holding area, enabling the CPU to manipulate data before transferring it to a device. For example, word processors use a buffer to keep track of changes to files. Then when you save the file the word processor updates the disk file with the contents of the buffer.

What is a file allocation table?A file allocation table is a table that the operating system uses to locate files on a disk. The name originates from the usage of a table which centralizes the information about which areas belong to files, are free or possibly unusable, and where each file is stored on the disk. To limit the size of the table, disk space is allocated to files in contiguous groups of hardware sectors called clusters.