THE PURPOSE OF OPERATING SYSTEMS

WHAT IS A OPERATING SYSTEM

The operating system is stored in the HDD (Hard

Disk Drive), it is the most important type of essential

software system in the computer. Without the OS

peoples computers would not be able to run as many

applications as somebody with OS. You would

normally be able to find Operating Systems in things

such as personal computers, SAT NAVs, network

servers, mobile phones, Games consoles, cars

etc. . . .

THE MAIN FUNCTION OF A OPERATING SYSTEM

Processor management

Memory management

Device management

Storage management

User interface

PROCESSOR MANAGEMENT

The OS controls the jobs sent to the CPU, as the processor

can only manage one job at a time, however can process 7000

jobs a second, which makes it look like it can multi-task.

The operating system also controls the buffer. The buffer

can hold multiple jobs that have been sent to the processor at

once, the buffer then records all the jobs sent by the input

device and gives it to the processor when it has finished its

previous jobs, essentially slowing down the job rate.

MEMORY MANAGEMENT

The virtual memory in the computer allows you to

run more applications than it has RAM for. The

reason for the virtual memory is to make the address

space bigger, e.g.: The virtual memory may have

twice as much space as the computer memory.

DEVICE MEMORY

Device memory is the part of the computer that

preserves the information that is stored in your

computer, this means that you can access it on your

PC at any time.

STORAGE MANAGEMENT

There are 2 types of storage on a computer:

Main storage- provides storage that can be accessed directly by

the CPU.

Secondary storage- there are three main functions of the

secondary system :

o Managing the free space on the secondary storage device.

o Allocation of storage space when new files have to be written.

o Scheduling the requests for memory access.

USER INTERFACE

User interface is in the space where humans and

the computers interact, things that allow you to

interact with the computer are the monitor, mouse

and keyboard, you make physical contact with these

things which creates user interface.