View
222
Download
0
Category
Tags:
Preview:
Citation preview
Section 4:Operating system
softwareBy Alex Melhuish
Typ
ical IT
Syst
em
?Operating system software
Learning objectives
Able to explain the 6 key functions of system software
Able to explain each using a suitable example
Identify three different system software interfaces
• B the system when the computer is first switched on
• I communication with each other• O of files on the hard disk• M during multi-tasking• A between tasks• S , user and file permissions, handling
errors
Functions of an operating system(Systems Software)
6AQA ICT AS Level © Nelson Thornes 2008
booting up the system when the computer is first switched on
7AQA ICT AS Level © Nelson Thornes 2008
managing memory during multi-tasking
• The operating system allocates processing time and memory to the various tasks that need to be carried out.
8AQA ICT AS Level © Nelson Thornes 2008
allocating processor time between tasks
• While computers seem to be able to multitask, a single processor can only do one thing at a time.
• Dual and quad core processors behave as if the computer has more than one processor.
9AQA ICT AS Level © Nelson Thornes 2008
controlling where data is stored on disk
• The operating system organises the storage and retrieval of data files from backing storage such as the hard drive.
• It keeps a directory of where the files are stored on disk.
• It keeps track of the free space on the drive so that files can be stored efficiently for faster retrieval.
10AQA ICT AS Level © Nelson Thornes 2008
communicating with input and output devices
The operating system needs to:• interface with peripherals
such as a mouse or printer• handle interrupts – signals
that need an immediate response, such as a mouse click to stop a file printing.
11AQA ICT AS Level © Nelson Thornes 2008
system security, user/file permissions, handling errors,
Types of interface
The operating system also provides the user different interfaces, such as:
Graphical User Interface
1
2
3
Recommended