GCSE ICT exam notes

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					GCSE ICT exam notes

Input   Peripherals (devices)
       Keyboard, including specialised keyboard
       Mouse, touch pad, tracker ball (like an upside down mouse), joystick
       Graphics digitiser (sometimes called graphics tablet)
       Touch sensitive screen
       Light pen
       Scanner, digital camera for photographs or video
       Microphone
       Sensor

Output Peripherals (devices)
    Screen (monitor or VDU)
    Printers (dot-matrix, laser, ink-jet)
    Plotters (draw graphs often linked to scientific equipment)
    Speakers, headphones
    Motors and switched output in control systems (light bulbs etc.)

Storage devices and media
    ROM (Read only memory) and RAM (Random Access Memory)
    Hard and floppy disks
    Magnetic tape
    CD-ROM, CD-Recordable, CD-Rewriteable
    DVD ROM, DVD RAM

Desk top publishing

Features of desk top publishing packages can be used to enhance the presentation of a leaflet:

       templates                      tables and tabs                bulleted lists
       use of white space             upper and lower case           justification
       titles and headings            subscript and                  columns
       fonts and sizes                 superscript                    special symbols
       bold and italic text           graphics                       headers and footers
       Word Art                       colour                         charts and graphs
       drawing tools                  borders and shading
                                       dividing lines (rules)



Control software

Cast your mind back to LOGO – control a robot by giving it simple commands

FORWARD     50
RIGHT 90
FORWARD     50
RIGHT 90               would draw a square of size 50
FORWARD     50
RIGHT 90
FORWARD     50

Spreadsheets

Spreadsheets are used to do calculations. You need to know how they work – specialised
terms. Cell is the name of each box on the grid they are referenced with a letter and number
(e.g. C5). You can format the data held in the cells in many ways, bold, centre, italics,
underline, certain number of decimal places, currency etc.
You need to be able to talk about the advantages of using a spreadsheet to do calculations
over pen and paper. You can save and edit work, alter the amount entered and all relevant
calculations will be recalculated and the new answer worked out without you having to do all of
the sums again etc. Can draw graphs.

Flowcharts

You need to be able to follow and add to a simple flow chart:



Sensors

Know the place of sensors in systems flowcharts. Think about
temperature sensors (thermostats) in central heating systems. They
constantly measure the temperature and if it gets too cold they turn the
heating on. If it gets too hot they turn it off/down etc.

E-mail

You need to be able to talk about electronic mail and the advantages /
disadvantages over other more traditional methods of communication. It
is a way of sending a message to somebody over the internet. You can
send attachments, so you can send pictures, business reports, video
clips…… you can also send it to more than one person at once. However,
you cannot be sure that the person has read or received it; it is less
personal than a letter or phone call. How secure is it?

Purposes of operating systems

The computers operating system is a program that controls the hardware directly. Operating
systems perform the following tasks:
They provide a way for the applications software to communicate with the hardware. For
example, in Word if you click on the printer icon the operating system gives an instruction to
the printer to start printing.
They manage the system resources such as memory and allocate central processing unit (CPU)
time to the task being run.
They manage the transfer of data to and from the various peripherals (keyboards, mice,
scanners, printers etc.)
They manage system security. Many operating systems allocate certain rights to users. A user
can only do certain things on entering a password.
The operating system provides an interface between the user and the computer hardware.
Without an operating system a computer would be useless. The first thing the computer looks
for when it is switched on is the operating system. Some software will only run with certain
operating systems e.g. Microsoft Word, Excel, Access etc. will only run with Windows 95,
Windows 98, Windows XP etc. operating systems.

User Interface

The user interface is what you see when you turn on the computer; it consists of the cursors,
prompts, icons, menus etc. which allow you to interact with the computer. Ideally the user
interface should be as user friendly as possible so it is obvious to someone who has never used
the software before what to do.
User interfaces can be:
     command driven
     menu driven
     graphical (referred to as a graphical user interface (GUI))
Graphical User Interface (GUI)
A graphical user interface provides a way for the user to communicate with the computer
through pictures (icons) and through pull down menus. Windows is an example of a GUI.

Command driven interface
With a command driven interface you type in a command (usually abbreviated) in order to get
something done. Command driven interfaces are not easy to use. In order to get the computer
to do things you have to remember lots of commands. These commands are rarely the same in
different packages so people often get them mixed up. Some people, mainly those who are
used to using them, prefer them to menu driven interfaces as once you have learnt all of the
commands they can be quicker to use.

Menu driven interface
This type of user interface produces all of the commands within a program as a list, or menu,
and the user can make a selection by using either a mouse or keyboard. Microsoft Windows is
a menu driven environment.

Networks – WAN and LAN

Networks come in two sizes – Local Area Networks (LANs) and Wide Area Networks (WANs). A
LAN is something like a small company or a school, the computers are normally all in one
building and communication is normally made via wires or cables. A WAN is when computers
are spread over a much larger area and communication is normally made via telephone lines
or satellite. A bank system may be a WAN where communication is maintained to a head office
from local branches.

Discuss the advantages and disadvantages of networks over stand alones
    Advantages Expensive peripherals such as laser printers and scanners can be shared
      amongst the networked computers
    Messages can be sent between users via an internal mail system
    All users can access the same files so this avoids file duplication
    Network software can be purchased which is usually cheaper than individual licenses.

      Disadvantages if a WAN is used sophisticated equipment is needed and the rental of
       telecommunication links is very expensive
      A loss in the ability to transfer data for even a short time can cause havoc, with tasks
       having to be performed manually
      File security is more important with networks. For example if a virus were to get onto
       the network then it could affect all of the networked terminals.
      Wiring can be expensive both to buy and to install. Wiring has to be sunk to avoid it
       trailing across a floor where it would be dangerous.

System life cycle

This is basically what you have done for your
major project. You will need to be able to talk
about what happens in the different sections.

Advantages and disadvantages of the
internet
There is always an essay style question. Make
sure you make your answers relevant to the
scenario in the questions.

				
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