Features of an Operating System - Riddlesdown Collegiate VLE

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14 Δεκ 2013 (πριν από 4 χρόνια και 7 μήνες)

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Features of

an

Operating Sy
stem

Scheduling

The task of handling how active processes are making efficient use of the CPU processing cycles is called scheduling. There
are many ways of doing
this, which is covered in the next lesson

Memory Management

The
operating system has to make sure that applications are able to run in the amount of memory available and that

they do
not interfere with one
another.

Allocation of resources



The operating system will provide a working area for each user. This includes



Di
sk space quota for their files ( especially on shared network drives)



A personal GUI set up for each user (multi
-
user operating systems)



Perhaps how many processing cycles they are allowed to use (especially on mainframe)



How much printer output they are a
llowed (networked and mainframe)



How high a priority they can assign to a job (mainframe)

Keeping track of usage

The cost of using large computers is shared amongst the users. So the operating system will have an accounting / tracking
system in place that
:



Counts the processing cycles used per user



Print out jobs completed



Batch jobs completed



Time spent logged in



Other resources used

And so on. A regular bill is then sent to the user account providing an itemised charge.

Data and User security

Each user

h
as to be authenticated with a

username and password (network an
d multi
-
user operating system).
Their data and
files will be kept private from other users, unless they choose to make some shareable with others.

The operating system will
only
allow administr
ators ('super users') to change parts of the operating system and install applications.

Providing system services such as print spooling

Printing out is a time consuming process, so it makes sense to allow users to hand
-
off a print job to the operating sys
te
m so
they can get on with other
things. This is called 'print spooling' and is common on multi
-
user and networked operating systems.

Managing input / output

Data and applications are stored on secondary storage devices such as hard disks, optical drives,

magnetic tape when not in
use. The o
perating system
has a file management system that allows the user to organise their files, to move, dele
te and copy
files as they wish.
Specialised input devices such as graphics tablets and scanners are also handled by

the operating system.

Handling Network communication

Data packets traveling to and from the connected computers on the network are handled by the operating system. When
an
user drags a file from their
hard disk to a shared networked drive, they do not
care how it happens
-

the operating system takes
care of all the details.