Information & Communication Technology 1996-2003

GCSE Revision

Computer Software - System Software

A systems program is a program which helps to control the computer's operations, for example, by selecting and controlling the input, output, and storage devices.

(You are only required to have a brief outline awareness of the following material at GCSE level. Much of the detailed content provided here is to help you piece together computer terms you may have picked up but have little understanding of.)

Disk Operating System (DOS) - provides the commands to control peripheral devices such as disk drives - format, copy, open, save, delete, print, etc. Examples are MS-DOS, OS/2 and UNIX (only one of these is needed on a computer). It is usually preinstalled as files on the hard disk and therefore easy for the user to upgrade.

Machine Operating System (CMOS) - controls the basic machine when it is switched on, telling it how to communicate initially with its various parts (hard disk, keyboard, etc) and is unlikely to need upgrading. Usually stored in a ROM chip.

Command Line Interpreter (CLI) - provides an interface between a human operating system (your brain) and the computer's operating system through the use of commands which have to be typed in at the keyboard onto a blank screen. For example: COPY C:\REPORT.DOC A: would copy a file called report.doc from the hard drive (C:) to the floppy drive (A:). These commands are provided as part of the operating system package and have to be learnt and remembered accurately by the user. Fortunately this is no longer absolutely necessary - see below.

Graphical User Interface (GUI) - provides an interface between a human operating system (your brain) and the computer's operating system through the use of pictures (as icons) and text (as menu options) provided on the screen. Examples are MS Windows 95 or 98  which include MSDOS as one complete package. All new computers now have an operating system and GUI pre-installed. Modern computers are now much easier to use as complicated commands no longer need to be learnt by the average user.

Utilities or Tools - programs which perform various management tasks. Examples are Pkzip or Winzip, which will compress files so that they are small enough to fit onto a floppy disk or transmit faster over the internet. Antivirus software which will run in the background and zap any viruses as soon as they appear. Quickres is a program that allows you to change your screen resolution without restarting the computer.

Hardware Drivers - programs which provide a translating interface between commands used by the operating system and commands used by your various hardware devices such as printer, scanner, monitor, modem, mouse, etc. These devices are produced by a wide range of different companies and are continually being updated and improved. An operating system will include many common drivers that were available at the time you purchased the computer. If you later buy a new device such as a printer, it will often be designed to work with the old drivers, but you will get more out of it if you install the new drivers that are provided by the manufacturer.


BackUp Page last updated 30/03/2002 I.D.Lee, Didcot Girls' School
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