Section 4 2 Unit 3 Section 4 2

Section 4. 2 Unit 3 Section 4. 2 Types of Operating System AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Types of operating system There are many different types of operating system. Some of the different types are: interactive, realtime, network, mobile device, embedded, desktop, server. They are not all mutually exclusive, e. g. you can have an operating system that is real-time and also embedded. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Interactive operating system The user interacts directly with the system. The user supplies commands and data. The results of processing are given to the user immediately. The user and the computer are in two-way communication. The operating system on your computer at home is likely to be an interactive OS. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Real-time operating system When an input is received it is processed in a timely manner. If no input is received in time then a time out will often happen and a default value will be used for the input. The output can affect the source of the inputs, so has to happen quickly enough for this to be possible. They normally need to be able to cope with multiple inputs happening at the same time. The Eden Project in Cornwall uses a real-time operating system on the computers used to monitor and control the environment in the greenhouses. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Network operating system This is a layer of software that is added to the operating system of a computer. It allows a computer to be connected to a network. It intercepts all commands that reference resources elsewhere on a network and redirects the request without the user knowing it is happening. In other words, it allows you to connect your computer to a network without you having to know how the network itself works. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Server operating system This is an OS that provides a specialised service to client machines on a network. Examples of services that may be provided include file storage, running applications, printer management and domain control. This specialisation results in a much better performance than could be achieved by a server conducting more general purpose processing. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Desktop operating system A general purpose operating system. Allows a user to carry out a large range of tasks and are very complex pieces of software. They tend to be written in a modular fashion to allow for easier updates. They take up a large amount of memory and take a while to load. AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Embedded operating system An embedded operating system is one that is placed inside a larger machine for the purpose of controlling that machine, e. g. a computer inside a DVD player. Inputs often come from sensors; outputs are usually actuators. They generally have no user interface (or a very limited one). Operating systems for these devices need to work with limited memory and processing power AQA Computing A 2 © Nelson Thornes 2009

Section 4. 2 Mobile device operating systems Mobile devices – such as a Smart. Phone – need an operating system. They often need to work in real time to cope with multimedia applications. Processing power and memory on these devices can be quite limited. They may need to cope with maintaining a network connection that can vary in strength due to the mobility of the device. AQA Computing A 2 © Nelson Thornes 2009