FUNDAMENTALS OF COMPUTER SYSTEMS

OCRGCSE Computing

2.1.1 Fundamentals of computer systems

Candidates should be able to: Define a computer system Describe the importance of computer systems in the

modern world Explain the need for reliability in computer systems Explain the need to adhere to professional standards

in the development, use and maintenance of computer systems

Explain ethical, environmental and legal considerations when creating computer systems

Define a computer system

Takes a set of inputs, processes them and creates a set of outputs. Using hardware and software.

Inputs provide data, the data is processed and the outcome is sent to an output. The output may be stored until it is ready to become an output.

Program

process

Storage

output

input

Examples of computer systems

A computer system

For processing to be done, there needs to be a set of instructions. This set of instructions is a program.

This system is called a stored-program computer.

Computer input

The role of an input in a computer system is to provide data for further processing.

An input is data or commands entered into the computer via an input device such as a keyboard, mouse, scanner, barcode reader etc.

See inputs and how they work doc.

Computer processing

Processing is the stage where the input data is manipulated in order to produce meaningful information.

The results from the processing can then be used in the next stage called “output”.

Processing can include stages such as sorting, searching, calculations or graphing.

Computer output

Output is the stage where the information obtained via processing is presented to the user in a suitable format.

You may be able to see the output as a printout or display on the computer screen.

You may be able to hear the output via music, voice instructions or a computer generated alarm.

See inputs and how they work doc.

Task 1

• Create a short presentation describing the importance of computer systems in the modern world. Include information about: Why they need to be reliable? Why must we adhere to professional standards in the

development, use and maintenance of computer systems? What ethical, environmental and legal considerations

must be considered when creating computer systems?

Standards

Proprietary standards: Standards owned by the company. E.g. Windows must handle data in a certain way, communicate with the operating system in defined ways and work with a defined interface.

Advantages Familiar look and feel to users which speeds up

learning new systems Improves reliability by working in a practical way Maintained by one company so minor updates are

usually free

Standards Cont.

Industry standards: Standards are agreed across the computing industry in particular with hardware. Allow easy interconnection between devices. E.g. USB which is the standard way of connecting devices to most computer systems.

De facto standards: Standards developed through common usage until they are the accepted way of doing things. E.g. Car controls, most cars have indicator stalk on the left of steering column

Standards Cont.

Open standards: Standards that are publicly available so software can be modified by users. For software, the source code is available for the public so anyone can make changes. Examples include world wide web, HTML, TCP/IP and C# programming language. Examples of open source software are Mozilla Firefox, the Android operating system, Moodle VLE and Python programming language.

Ethical, environmental and legal issues

Ethical employment

Environmental energy efficiency creation & disposal of hardware

Legal The Data Protection Act, The Computer Misuse Act The Copyright, Design & Patents Act