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.