In this section I tried to give answers to the following questions:
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An Operating System (short: OS) is software that acts as an
intermediary between a user of a computer & the computer hardware. The purpose of
an operating system is to provide an environment in which a user can
execute programs in a convenient & efficient manner.
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The Operating System has to perform the following tasks:
- provide the user with the possibility to control the OS' activities
and to enter system commands (command interpreter)
- maintain a list of hardware components and how they are used
(device drivers)
- decide which jobs are executed in what order
- allocate and deallocate memory that is needed by the jobs
- Keep track of which parts of memory are currently being used &
by what process
- organize and control all files that are stored on local and remote
storage media
- set up and maintain a protection system that makes sure that several
jobs running on a computer are not overwriting each other's data
- handle all Input/Output (short: I/O) operations inside and
outside the computer
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According to the tasks an Operating System has to perform, its components
are usually identified as follows:
- Memory Manager
(allocates and deallocates memory that is needed by the jobs)
- Process Manager
(decides which jobs are executed in what order)
- Device Manager
(handles all Input/Output (short: I/O) operations)
- File Management
(organizes and controls all files that are stored on local and remote
storage media)
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Table: Responsibilities of Operating System's parts
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RAM
ROM
EEPROM(s)
Cache
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Processor(s)
Coprocessor(s)
Processes
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Memory
Manager
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Process
Manager
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Disks
Tapes
Output devices
Input devices
Controllers
Buffers
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Device
Manager
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File
Manager
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Files
Allocation tables
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