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Computer Systems
What are computer systems?
A computer system comprises of hardware and software, along with any peripheral
device required to operate it.
Computer systems may take a range of forms, for example: desktop personal
computers (PCs), laptops, tablet devices, programmable toys, smart phones,
televisions, onboard monitoring systems in cars or control units in ovens or
washing machines.
Examples of computer systems around the home.
The national curriculum for computing makes reference to digital devices in the
key stage 1 statement:
“Understand how algorithms are implemented as programs on digital devices”
A digital device may be considered any computer system used in the classroom, including programmable toys such as Bee-Bots, Roamers or Pro-Bots, or
computer systems such as desktop PCs, laptops or tablet devices.
:
Examples of ‘digital devices’ as mentioned in the computing national curriculum.
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In 1945 John von Neumann devised a model to represent the processes of a
computer system. Whilst computer systems can vary in form and be programmed
to carry out a number of different tasks, they always use the same simple process,
namely:
•Receive information via an input.
•Store this information for use in processing.
•Process this information and store as required.
•Generate information through an output.
Diagram illustrating the Von Neumann model of a computer.
Computer systems consist of both hardware and software. The hardware includes
inputs, processors, memory, a motherboard and outputs.
Inputs: in order to receive information, computer systems require inputs. On
programmable toys such as Bee-Bots or Roamers buttons are used to input
information. On desktop PCs, laptops or tablets there are a range of inputs such
as a keyboard, mouse, microphone or touch screen. Computer system inputs are
explained further here.
The buttons on a Bee-Bot and the touch screen on a tablet are both examples of inputs.
Processor: A processor is used to process information within the computer system. It is the processor in a computer which carries out the instructions of the
program and enables the computer system to perform tasks.
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A typical processor found in a personal computer.
The processors used in personal computers are similar to those used in mobile
devices. The image below is of Apple’s A7 processor which is used in the iPhone
5S, iPad Air and iPad Mini (2nd generation).
The processor within Apple’s iPhone 5S. Public domain.
Memory: Computer systems have various types of memory components which
are used to store information. Some store information temporarily (Random Access Memory – RAM) whilst it is being used by the processor, whilst others provide
more permanent storage, such as the hard drive in a laptop. Memory devices store
data in binary form (either 0s or 1s). Memory is measured in bits and bytes. The
amount of memory needed to store a file depends on its type and the complexity of
the data.
•1 Bit can hold a 0 or a 1
•1 Byte can hold 8 bits, which could store one character e.g. an ‘A’ – there are
128 characters in the standard 8-bit set.
1 Kilobyte (Kb) holds 1,024 Bytes, which might store a paragraph (150 words of
average 5 letters each).
1 Megabyte (Mb) holds 1,024 Kilobytes, which might store a few images.
1 Gigabyte (Gb) holds 1,024 Megabytes, which might store a short video or lots
of text (equivalent to 150 copies of the Q’uran and Holy Bible).
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•
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Computer systems with a dedicated function, such as programmable toys, control
devices for central heating systems or fuel flow regulators in car engines, are typically constructed from a microcontroller, as shown below. These will include both a
processor and memory in a single chip. Computer systems such as these are configured during their construction to carry out dedicated tasks. Some are programmable such as those in calculators, alarm clocks and central heating systems.
Some are ‘fixed’ such as electric razors.
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A microcontroller combines both a processor and memory.
Public domain
Motherboard: A motherboard is the main circuit board found in a computer system. A photograph of the Raspberry Pi motherboard appears below. The hardware components in a computer system, such as the memory and processor, are
mounted to the motherboard as are peripheral devices via a variety of ports. The
motherboard enables the transfer of data between components via buses, which
pupils learn about at KS3.
The motherboard on the Raspberry Pi.
Outputs: Once a computer system has processed the inputted information, it will
output this information to a user in a number of ways. For example, the output
on a programmable toy is that of the motors which will cause the device to move.
Typical outputs for a laptop include the screen and speakers. Computer system
outputs are explained further here.
The screen on a laptop is an example of an output, as are the speakers.
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Software
On computer systems such as desktops, laptops, tablets and smartphones, it is
the software which enables the system to be flexible in meeting a range of user
needs. There are different types of software which run on these computer systems:
Operating system
The operating system enables the various hardware components to communicate
and function together and provides the user with an interface to operate the computer system. It is also the operating system which enables other software programs to be installed, called application software.
There are different operating systems available for different computer systems, the
most popular examples include:
Android: This is designed for touch screen mobile devices.
iOS: This is specifically designed for mobile devices created by Apple.
Linux: Is a free and open source operating system.
OS X: Is the operating system developed by Apple to run exclusively on Apple
computer systems.
Windows Phone: A version of the Microsoft Windows operating system for mobile
devices.
Microsoft Windows: Is the operating system developed by Microsoft for a range
of computer systems.
Below is a screenshot of the Apple operating system OS X.
The Apple operating system OS X
Application software
Application software refers to software on a computer system which enables the
computer system to perform specific tasks beyond the running of the computer
system itself. Examples of popular application software include:
•Microsoft Office – for word processing, creating presentations or spreadsheets
•Smart board or Promethean presentation software
•Mobile banking apps – applications running on a mobile device allowing access
to banking information
•Movie editing software
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Programmer development kits
It is also possible to run programmer development kits, such as Scratch, Greenfoot, Visual Basic and JDK within an operating system running on a computer
system. These enable programs (application software) to be written.
Scratch is an example of a programmer development kit. This can be run within an operating system
on a computer system and used to write programs (application software).
Why are computer systems important?
Computer systems surround us all the time, from the alarm clock that wakes you
up in the morning to the TV you watch of an evening. They are used in communication, business, scientific research, transportation, education, sports and media.
They are part of our daily lives. The vast majority of us use computer systems
each day at work, whether you are a teacher using a laptop and interactive whiteboard in a lesson, a shop assistant monitoring a shop’s stock, a designer running
graphics software or a programmer writing code.
Nowadays the computer system likely to be the closest to you for the greatest time
is a smart phone. Smart phones enable us to undertake a multitude of tasks, via
the installation of ‘apps’, from browsing the world wide web, playing game, making
video calls, playing music or reading newspapers.
The portability of these computer systems means they also have become ideal
for acting as an input/output device for other computer systems to connect to the
internet whilst on the move. This functionality is called ‘tethering’ whereby you can
utilise your smart phone’s mobile communication technology and configure it as a
Wi-Fi (Wireless Local Area Network) hotspot for another computer system. This is
shown in the diagram overleaf:
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Diagram illustrating tethering.
What do computer systems look like in
the primary curriculum?
EYFS
Pupils will have the opportunity to use a range of computer systems including
programmable toys, desktop PCs, laptops and tablet devices. Pupils will develop
an awareness of how to interact with these as they use a range of input types, and
will observe outputs in a range of forms, including movement from programmable
toys and visual and audio outputs from other types of computer system.
Throughout EYFS and early key stage 1 peripheral devices used to control the
computer systems may be simplified to aid pupils’ control, such as large button
keyboards and mice.
KS1
Understand how algorithms are implemented as programs on digital devices
Pupils’ developing experience of using computer systems will help them to understand how to implement algorithms as programs on a range of digital devices. For
example, they will use the input buttons on programmable toys, such as Bee-Bots
or Roamers to enter directional commands. If using graphical programming languages running on tablet devices, such as ScratchJr, they will manipulate these
programming environments via the device’s touch screen as they construct a
sequence of commands to implement their algorithms.
Pupils will continue to use a wide range of computer systems and become more
proficient in the manipulation of these through the use of a variety of input devices.
KS1
activity
Bee-Bots 1,2,3 Activity
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KS2
As pupils undertake projects in which they create digital content and programs,
such as a short film or program in Scratch, they may use a range of different
computer systems with a variety of software. For example, in the case of making
a film they might use a tablet device which features a camera (input) to record film
footage. Pupils might then transfer their footage to a desktop computer running a
video editing suite. In doing so pupils are using an output on the mobile device to
connect to an input on the desktop. The transferred footage is stored in the desktop’s hard drive. When transferring and storing data pupils will develop an understanding about the size of the data files as this will determine the time taken for
transfer and where they’ll fit!
As pupils work on editing their short films they will use application software running
on the desktop computer system. Pupils will typically manipulate this application
software through the use of the keyboard and mouse inputs and be able to observe the results of editing decisions as the application outputs information through
the monitor and speaker. Once pupils have completed their films, the processor
may convert the video project file into a form more suitable for viewing, which may
then be saved to the computer’s hard drive and shared with others by uploading
to a video streaming website via the ethernet connection or saving to an external
hard drive or CD-ROM.
Work with various forms of input and output
Pupils create programs which utilise a variety of input and output devices. For example they might use a keyboard or mouse to control a sprite within a game – the
information of the game being outputted on a monitor with sounds played through
speakers. Pupils might create programs that use a microphone or camera as an
input to trigger actions, such as a warning being displayed if the noise level is too
great! Pupils might also use tilt or distance sensors to control programs or toys
they have created. Such toys may also be controlled using motors, another form of
output from a computer system.
KS2
Investigating Inputs Scratch Activity
KS2
Working With Outputs Lego WeDo Activity
activity
activity
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Understand computer networks including the internet; how they can provide multiple services, such as the world wide web.
Pupils learn that computer systems can be connected to form a network in order to
share resources, and that the internet is made up of millions of computers systems
connected across the world. They take part in activities where they model the internet to learn how it provides services such as the world wide web. In doing so they
learn that computer systems exchange data via their inputs and outputs.
KS2
Modelling The Internet Activity
KS2
Network Hunt Activity
activity
activity
Find out more about computer systems
Computing in the national curriculum – a guide for primary teachers
Wikipedia page on computer systems
Wikipedia page on software
The Open University page on computer systems
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