OCR GCSE Computing - Deyes High School

GCSE 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
 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.
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 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
 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
 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
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?
 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.
Familiar look and feel to users which speeds up learning new
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
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