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The purpose of operating systems

Features of Operating Systems
An operating system is "the name given to the collection of systems software that manages the computer". The actual facilities provided by an operating system will very much depend upon the design and type of facilities needed by a particular set-up. The needs of the following systems will all vary.
 
    • A batch processing system such as a bank-statement producing system.
    • A real-time system such as a system controlling a plane.
    • A personal computer.
    • An embedded system as found in, for example, a microwave or dishwasher.
    • A network with many users, as found in many schools.
    • A tablet.
    • A mobile phone.

For example, a real-time operating system may not have any need for memory management routines because the program and data to run a washing machine are held in ROM. There is no need to transfer data between RAM and secondary storage.

The features of personal computer operating systems
A PC operating system is a collection of programs and utilities. These manage the computer's hardware and software. The operating system looks after the basic functions of the computer. A computer is made up of a number of different components that have been connected together. Once connected to make a 'computer', however, the components don't start working together until an operating system takes control.

The operating system, then, manages the basic functions of the computer. The jobs done by an operating system can be summarised using the following diagram.

OS

The basic functions of an operating system include the following:

    • Making sure all the parts of the computer can work together.
    • Making sure that the user can interact with the computer by providing an interface.
    • Ensuring that any errors in the computer are reported to the user, usually with messages on the VDU.
    • Managing files on the hard drive and in memory and allowing the user to manage files by providing a file management utility program.
    • Making sure that data can be entered into the computer, displayed or saved by providing software that allows data input and output.
    • Providing utility programs such as FORMAT DISK, FILE MANAGEMENT or DEFRAG.
    • 'Scheduling'. The operating system provides programs that ensure the resources of the computer such as CPU time, are used as efficiently as possible by all the different users and the different jobs.

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