The operating system Cambridge IGCSE Computer Science (9–1) revision
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In plain words
The operating system is the software that runs the computer. It sits between the hardware and everything else, sharing out the processor, the memory and the devices among the programs that want them, and giving you a way to tell the computer what to do.
7 things to know
- Managing files: it creates, names, saves, moves and deletes files, and organises them in folders.
- Handling interrupts: it responds to signals from hardware and software that need attention.
- Providing an interface: it lets the user communicate with the computer, for example through windows, icons and menus.
- Managing peripherals and drivers: it controls the devices attached to the computer, using a driver for each one.
- Managing memory: it decides which program uses which part of RAM, and keeps programs from overwriting each other.
- Managing multitasking: it shares the processor's time between programs, so that several seem to run at once.
- Providing a platform for running applications, providing system security (such as passwords), and managing user accounts.
Worked example
A user prints a document while listening to music and typing an email. Which functions of the operating system are at work?
- Three programs appear to run at once: that is managing multitasking.
- Each needs its own share of RAM: that is managing memory.
- The printer is controlled through its driver: that is managing peripherals and drivers.
Tips and tricks
- There are nine functions in the syllabus. Learn them as a list, and be ready to describe any one in a sentence.
- A driver is software that lets the operating system communicate with one particular device.
It lands in your notebook with its questions as flashcards.
The operating system: 5 questions and answers
These are the quiz’s questions. Do the quiz first, then come back here for the ones that got you.
Which of these is a function of an operating system?
The others are done by application software.
What is a driver?
Each printer, scanner or camera has its own.
Which function lets several programs appear to run at the same time?
The processor's time is shared between them.
Windows, icons and menus are part of which function?
The interface is how the user and the computer communicate.
Giving each person their own login and settings is:
Each account can have its own files and permissions.
Quiz
5 questions
Tap an answer and you’ll see straight away whether it’s right, and why.
Worksheet
2 questions, 6 marks. Write your answers on paper, then check them.
The operating system
Cambridge IGCSE Computer Science (9–1) 0984 · 6 marks · papermunch.org
Name ______________________________ Date ______________
Describe two functions of an operating system.[4]
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Managing memory: it allocates RAM to each program and stops programs using the same part. Managing files: it lets files be created, saved, renamed and deleted, and organises them in folders.
Explain what is meant by multitasking.[2]
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Several programs appear to run at the same time. The operating system shares the processor's time between them.
Answers: The operating system
- 1. Managing memory: it allocates RAM to each program and stops programs using the same part. Managing files: it lets files be created, saved, renamed and deleted, and organises them in folders.
- 2. Several programs appear to run at the same time. The operating system shares the processor's time between them.