2. WHAT AN OPERATING SYSTEM IS…
An operating system is the first thing to be loaded on to your computer. You will
not always personally load it up yourself as the it will have already been
pre-loaded on to your computer, without the operating system your computer
would be useless.
Operating systems have now started to be built into small computers and games
consoles such as netbooks, XBOX 360, PlayStation, laptops and even mobile
phones.
The purpose of operating systems is to manage the hardware and software
which then allows the device that it is in to act in an ordinary fashion. In PC's the
operating system controls many things such as the memory, the processor and
the keyboard/keypad.
3. DEVICE DRIVERS
The driver is a program which makes a
pathway for pretty much all of a
computers hardware that is not
connected to the motherboard. The
main function of the Driver is to
translate data sent from the operating
system into data that the different
types of hardware are able
to understand, but due to the amount
of different types of hardware there are
differences in which the driver runs.
The driver allows higher level
computer programmes to connect to
the hardware.
4. DEVICE DRIVERS
The reason for the driver being
separate from the operating system
is because it allows you to add new
functions to it. The device driver can
be made into logical or physical
layers. The logical layers process
the data for a group of devices like
Ethernet cables or disk drives.
Whereas the physical layers
The driver normally communicates
with other devices via buses or by
the computers subsystem in which
the device is connected to.
5. OPERATING SYSTEM APPLICATIONS
Single user, single application operating
system: this is an operating system which is only
used by one person at a time and is only
capable of running one application at a time.
Most of the devices which use this
application are standard mobile phones.
Single user multi-tasking, this is the sort of
operating system which is built into your ordinary
personal computer. Although designed with the
single user in mind you can run lots of different
applications at the same time. This is better than
the single user, single application operating
system because it is able to run lots of different
apps at the same time whereas the single user,
single application operating system can only run
one app at a time.
6. OPERATING SYSTEM APPLICATIONS
Multi-user, multi-tasking operating
system: This is the sort of operating
system used on mainframes and
supercomputers. They are designed to
be able to cope with lots of different
people on lots of different applications at
the same time.
With this the operating system needs to
make sure that the requirements of every
user on the server is balanced, and that
each program that is being used on the
server has enough and separate
resources so that if there is a problem
with one user it doesn't affect the entire
server.
7. MEMORY MANAGEMENT Input / output management
The Operating system needs to make
sure that the applications are able to When data and applications are not being used they
run with the amount of RAM on the are stored onto thing like the hard disk, optical drives
computer available and also that the and magnetic tape. Input/output management on the
memory on the applications does not operating system allows control of access to
interfere with one another. programmes to resources via the driver.
There are two different places where
the operating system manages the
memory. The logic address- this is
powered by the CPU and is also known
as the virtual address. The physical
address- this is the address which is
seen by the memory unit.
8. USER INTERFACE
The three main user interfaces used today are windows, Linux, The user interface is said to
and Macintosh. The user interface brings the structure and be one of the most important
communication between the user and the computer. User parts of any computer
interfaces are a set of commands or menus which allows the program because it
user to interact with the different programmes on their
determines how easy a user
computer. There is a command driven interface which can only
is able to make a program be
be run by commands, there is also a menu driven user
interface which is run by commands from the user selecting
able to do what you want it
from a number of choices from the menus which are displayed to.
on your screen.
9. Storage management
GUI
This is the term commonly used when talking
about the tools, processes and policies that
GUI the acronym for graphical user interface is are used when your computer is storing
an interface that takes advantage of your networks and storage services like
computers graphical capabilities and then virtualization and replication. When
makes programs easier to use. The more applications are loaded onto the memory the
advanced and well designed GUI’s save the
operating system loads them into block sizes.
users learning complicated command
If the block size is 4KB then every process
languages. But people who already know the
command languages prefer to use the
which is then loaded will be given a chunk of
command driven interfaces rather than the memory which is a multiple of 4. Applications
GUI. are then loaded in the fixed block sizes. This
helps to ensure that applications wont be
loaded up on top of each other memory space.
10. PROCESSOR MANAGEMENT
The main reasons for processor management are: to ensure that each and every process and
application is given enough time from the processor to be able to run properly, to use as many
processor cycles as possible for real work.
There are a number of different processes that run without giving you any clue that they are
even there. The application you can see such as, word processor or spread sheet are both
processors but could cause up to several different processes to begin, for some tasks like
communication with other devices or computers.
