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Operating Systems System Software, functions of an operating system

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The Operating System The Operating System is also known as System Software. All computers must have an operating system in order to work The OS is responsible for all the functions of hardware and also software

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Functions of an Operating System GUI Device Drivers Security Networking Disk Managem ent (File Systems) Memory Management Process Management Operating System

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Process Management A multitasking OS allows the computer to perform many different tasks(processes) at the same time The CPU can only focus on one process at a time. The OS tells the CPU to give each process a very short time slice (time slot) This happens very fast making it seem like the processes are occurring at the same time

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Memory Management A computer has different memory types it could use; memory registers, cache, RAM and disk storage. The OS is responsible for checking; which memory if free which memory is to be allocated and de- allocated how to swap between the main memory and secondary memory

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Memory Management When the OS swaps between main memory and secondary memory we call this Virtual Memory management Virtual memory creates a memory slot acting as RAM when the RAM is too full Virtual memory is much slower than RAM

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Disk Management / File Systems Operating systems have different file systems. A file system is an organisation of all the files and folders saved within the computer Each OS has a different file system hence a different access system (notes page 29)

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Networking Most of the OSs today are capable of using the universal TCP/IP (Transmission Control Protocol/Internet Protocol) This allows computers to communicate with each other and be able to share resources such as files and hardware devices over a network, such as Internet.

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Security The basic type of security an OS offers is asking for a Username and Password before a user can use the OS The OS could also limit certain users from doing certain actions. This is known as level access The OS uses a Firewall to close certain ports when using TCP/IP protocol

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GUI Graphical User Interface Most operating systems use a GUI Graphical User interfaces, which is more user-friendly as it uses graphical representations which the user can easily understand. A GUI's components are Icons, Menus, Windows, Toolbars, Buttons amongst others.

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Windows GUI

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Linux GUI

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MAC GUI

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Device Drivers A device driver is software that is responsible for the communication between different hardware and the computer. Device drivers are used to let the OS know how a specific hardware works as with all the new advances in technology it is impossible for the OS to know how ALL types of hardware work