Printers – There are a number of different forms of printer available on the markets that use different means to imprint the information on the paper. The various printer mechanisms create different quality of output and hence the price of the device. Despite the fact that the data is stored electronically there is still a demand for obtaining hard or paper copy of the documents.
Plotters – Plotters are available in two main types:-
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Flat Bead Plotters – The paper lies flat on a bed and a set of ink pens moves across the paper to create the image. The pens are mounted on a carriage and by a combination of the movement of the carriage across the paper and the pens along the carriage all the various shapes can be printed. Colour pens can be included to enhance the image. This type of plotter is available in various paper sizes.
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Drum Plotter – The paper is attached around a drum and attached to sprocket wheels at each side. The pens are mounted in a carriage that is fixed across the paper the full width of the drum and the pens have the ability to move across the carriage. This provides movement in only one direction. The paper is moved backwards and forwards to create the other form of movement needed to create the shapes and images.
Loudspeaker – Modern microcomputer systems can produce sound as well as visual and printer images. To achieve, this, a sound card is added to the computer and a pair of small loudspeakers. This enables the user to use software with a sound output, play music and receive sound over the internet.
Controlling Devices – A controlling device is any device that controls an activity. In our greenhouse, there would be two controlling devices, one controlling the opening and closing of windows and the other controlling the turning on and off of the heater.
Processing Unit
The main processing unit is the hardware that processes the data that comes from the input devices and sends it to the output devices.
In a word processor, words are keyed in using the keyboard and the processor sends the words to the screen. When the mouse is used to change the words, the processor receives the commands from the mouse, alters the words and sends the altered words to the screen. The words are called text.
In a spreadsheet, numbers are keyed into the computer; the computer carries out the calculations and sends the numbers and the results of the calculations to the screen.
The main processing unit includes the central processing unit, the input and output ports (connectors), the controller boards and the memory. This is the unit that carries out the main processes in the computer.
It has three main components:-
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The Control Unit – the control unit acts like the conductor of an orchestra ensuring that all the other components including the input and output devices carry out their functions correctly. It ‘fetches’ each instruction, interprets its meaning and overseas its execution. It is electronically linked to all of the other components so that it can detect if the required device or component is connected, ensure that the device is aware and ready to carry out the instruction and in the absence of the device, arrange to display an error message on the screen to alert the operator.
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The Arithmetic/Logic Unit (ALU) – All mathematical calculations and operations such as addition, subtraction, multiplication and division are carried out by the ALU. The items of data to be the subject of the calculations. Are temporarily transferred to the ALU, the operations performed and the answers returned to main storage.
It is also used to make ‘logical’ comparisons, many of which determine the route taken through a program. For instance a particular routine may only be called if the value of a particular variable is equal to zero. The value of the variable held in storage will be transferred to the ALU, its value compared with zero and reply transmitted back to main storage.
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Main Storage – The Main Storage of the machine stores all of the data to be processed. The items are entered from an input device. This could be a component such as a keyboard or even another storage device such as a diskette containing a data file. The data will reside in memory while it is processed. It will then be joined by the results of the processing, which will be held until it is transferred to an output device.
Also resident in this area will be the program that is responsible for the processing.
Main storage provides the processor with fast access to the information it requires. The various processes that are undertaken require different facilities to be available for the storage of the data and program instructions. Therefore, there are various types of memory, the most common of which are ROM, Read Only Memory, and RAM, Random Access Memory.
In many computers an area of cache memory is included in the specification. Many of the devices used for storage, such as disk drives, operate at a slower speed than the processor. The components that make up the cache provide the facility of fast access speeds and are inserted between the processor and the slower devices.
Another type of memory is called auxiliary memory. These are in effect both input devices and output devices, i.e. they are input-output devices. Data can be read in from them into the computer and output to them from the computer. An example of this type of memory is the disc.
Storage Capacity
Computer storage capacity is measured in terms bytes. The smallest data item is stored in a computer is a binary digit called a bit. A byte is eight bits in size and can store a character such as a letter or punctuation mark. A thousand bytes is called a kilobyte and a million bytes is called a megabyte or Mbyte. A thousand megabytes is called a gigabyte or Gbyte. A thousand gigabytes is called terabyte.
Microcomputers bought today commonly have 64 megabytes of internal memory and many 128 or 256 megabytes.
Software
A name for all types of computer programs e.g. Word, Excel.
Operating Systems – An operating system (OS) is a set or suite of programs created to optimise the use of the computer. The most common operating system used in microcomputers is MS-DOS (Microsoft Disk Operating System). The act of switching the computer on initiates the running of a program which will test that the components are functioning and which will be completed with the display of the system prompt (C:\>) indicating that the C drive is current) to make the user aware that the machine is now ready for work. If the name of a program is entered at this time the OS will arrange for the program to be loaded into the correct area of main storage. An area will be set aside for the data generated by the program and when necessary the OS will arrange for the data to be transferred into the ALU for processing and for the return of the answers on completion. The operating system will control the direction of the data to and from the correct input and output devices and produce a warning when the required device is not connected or the transfer has failed. This will include transfers to and from auxiliary storage and printers.
Operating systems provide a language with a limited vocabulary to enable user routines to be developed. One of the uses of the language included in MS-DOS is for the development of a batch program. When the computer is switched on and the checking routines are complete the OS will search the directory for the presence of a batch program and if it finds one it will automatically run it. Such a program could be written to display a particular screen layout at the beginning of processing to perhaps list for the user the names of the application that are available. This is known as providing a front end.
Graphics User Interface (GUI) provides a friendlier environment for the user. It provides brightly lit screens, icons, windows, drop-down menus, buttons and rulers.
Each icon represents a task and if it is selected by pointing and clicking with the left mouse button, the associated task will carry out. The act of the selection causes software to be run that will carry out the desired task. The Microsoft Windows screens provide the most familiar graphics user interface.
Graphics user interfaces enable the user to manage both system and application tasks without understanding how many of the tasks are achieved. Users can format disks, look after the files stored on the disks, change a number of the physical details of the screen display and specify the interaction of the computer and any peripheral device to which it is connected.
Applications can be loaded and once in place the operations included in the application can be initiated in the same way, normally by selecting the required option from a list in a drop-down menu.
Applications packages use similar screen formats with similar instructions located in the same place. This provides a form of comfort for the user and increases their familiarity with Windows-based packages.
Application Software – Application software programs can be:
- Written and developed using a programming language,
- Bought as a commercially available package, or
- Developed using the facilities of a commercially available package.
Programming Languages – When computers were first introduced the program instructions were strings of binary digits and programmers had to provide details of the functions to be performed and the storage areas to be used for the various values used in the processes.
This type of language is a machine language.
In a machine language, a program code for writing a value might be represented as
It was very difficult to work in binary – pages and pages of 0s and 1s are hard to read. Because of this assembly languages were introduced that used a series of mnemonics to represent the instructions and names to present the memory locations.
The instruction above might become
WTE LENGTH
With assembly languages it was still necessary to maintain a knowledge of the memory map to be aware of the whereabouts of each of the stored values.
These were known as low level languages because they were machine-oriented.
With the growth of computers, high level languages were introduced to enable programs to be written to solve commercial problems. The instructions were prepared using a normal vocabulary such as read, write, print and input, and mathematical operators such as =, + and -.
However, the computers still want their instructions in machine code so, once completed, the programs are converted into binary representation using a piece of software called a compiler or interpreter. During this process the storage addresses of each of the variables is allocated.
Commercial Software – It is possible to purchase a ready made, off-the-shelf generic solution to most commercial problems.
Unfortunately, because the package has been designed to be used by a number of different types of organisation, its facilities will usually never quite fit a particular situation. This may require a compromise to be made. A decision has to be made as to how much of a compromise the user is prepared to make.
A software licence has to be purchased in order to use a package. Such a licence will refer to the number of copies that can be in use at any one time. Illicit copying of the software is an offence punishable in law. Any purchaser should be sure about the capabilities of the package before obtaining it and to cost the implications of such a purchase. It may well be necessary to replace all of the printed stationary within the organisation to fit the requirements of the package and this item alone could be prohibitive. Packages provide a fast solution to problems. Keeping the packages up-to-date is the responsibility of the package producer. Updated packages may be supplied through the licence agreement or a maintenance agreement.
Adapting Commercial Software – Many of the generic packages are now accompanied by a form of programming language which allows for the package to be customised to fit more closely the needs of the organisation purchasing it. This could make the purchase of the package a more likely solution but does require having someone that understands the language, to provide an efficient solution and to maintain the program so that it can absorb changes in the processes that will evolve from its use.
There are different types of application software that can satisfy the user’s needs which includes:
- Word Processing,
- Desktop Publishing,
- Database Management,
- Spreadsheets,
- Graphics,
- Programming Languages,
- Utilities,
- Calendars and diaries, and
- E-mail.
Task 4
System “Configuration requirements”
Configuring the System
The operating system can be used to configure the system to meet the needs of the user. These include:
- Setting time and date,
- Organising the desktop,
- Setting passwords,
- Organising the structure of folders and files,
- Setting the display,
- Configuring the mouse, and
- Carrying out anti-virus checks.
Setting Time and Date – Facilities are available to set the time and date. For instance in Windows this is done through the Control Panel. Settings are made using the Date/Time properties dialog box.
Organising the desktop – The Windows environment consists of a desktop, menus and a number of windows. When you work on your computer all your activities take place in windows; a window being a rectangular area of the screen. You may run one application, say, a word processor in one window, and another application, perhaps a database system, in a different window.
The tasks that you are currently running are held on the Taskbar, usually at the bottom of your desktop. The desktop holds icons for some of the programs that are available to you. Some of your software can be accessed through the Programs menu. You have the choice of whether to display the software icons or have only on the Programs menu.
The desktop icons can be moved around the desktop and the Taskbar can be moved to the side.
Organising Folders and Files – The Windows operating system uses a software program, Windows Explorer, to help you organise and maintain your files, which may be on your hard disk or your floppy disk. To run the Window Explorer, click on the name in the Programs menu. This will produce a window shows folders and files. The left hand side of the window shows folders and the right hand side shows the contents of the selected folder on the left hand side.
Selections can be made by double-clicking on the items on the right hand side of the window or by clicking on the arrow in the drop-down list box at the top left of the window and selecting with a single click from the list produced. A click on desktop shows the top level structure of the desktop.
Files and folders can be moved, copied and deleted using this facility.
Setting the Display – In windows, display settings, such as screen resolution, background, screen server and screen colour, can be altered through the display Properties dialog box which can be displayed through the Control Panel or by right-clicking on the desktop and selecting Properties.
The Mouse – The Mouse Properties dialog box can also be displayed through the control Panel. This allows the mouse buttons and pointer speed to be configured.
Setting Passwords – In Windows, system passwords can also be set through the Control Panel and the passwords Properties dialog box.
Initiating Anti-Virus Checks – It is very important to protect your computer from viruses. To do this, anti-virus software has to be installed. Once done, it can be used to check any of the storage devices on your computer system using a command from the operating system.
Mrs Jones will need a selection of folders so she can categorise her work, this will help her because her files will be kept in selected folders and will enable her to access them more easily.
Task 5
The screen dump below shows, Window Explorer when right clicked on the start button of my Unit 3 Folder:
To suit Mrs Jones’ requirements, I am going to configure Mrs Jones’ system. Below, I am going to show how I configured her system:
Creating a Directory
Before: After:
Date and Time
Before: After:
Mouse
Before: After:
Keyboard
Before: After:
Printer Drivers
Printers and Faxes Printer Wizard
Task 6
Working Safely
The environment for those working with ICT is relatively safe, but there are hazards and many people suffer physical damage using computers over a long period of time. It is important to avoid problems arising from bad posture, long periods in front of the screen and poor layout of furniture and equipment.
Schools and colleges have to adhere to the Health and Safety at Work Act. In organisations, both employees and employees have responsibility in law to ensure a safe and healthy working environment.
You should have a comfortable working position at your computer and you should not be looking at the screen for long periods of time – it is suggested that you take a break from the computer every two hours.
Accuracy of my Work
When you are producing documents, it is important that they are easy to read. If not, the reader will struggle to follow the document, may get annoyed and may stop trying to read it. This could be a disaster for you.
Word processing software provides the facility to help the user to produce readable documents. It will provide a spell-checker, which is a piece of software which checks each word in a document and if it does not recognise the word as being spelt correctly, will tell you so you will offer you some correctly-spelt alternative words.
Sometimes it will not recognise a correctly spelt word, and you do have to accept the suggestions. People’s names and addresses often provide this type of difficulty.
Some spell-checkers will only check a document when you ask it to and others will check each word as you type it.
Word processors also have grammar checkers. They look at the way have written your sentences and will offer alternatives. They will, for instance, check that the each sentence starts with a capital letter, ends with a full stop, and has a subject and verb that agree.
As well as using computer software to check documents, you will have to be able to proof-read them. This is the difficult process of reading a document carefully for errors and then marking them up for correction using standard symbols.
Backup of my work
A backup is a copy of data and should be kept separately from its original. It is imperative that all files be backed up on a regular basis. The backup should be stored on a separate medium, such as tape or floppy disc. The backups should also be stored in another location; another building, another room. If this is not possible, the backups should be stored in fire-proof safes.
A well managed system will have a good backup procedure in place. The backing up of files should be done on a set day, at a set time to ensure that the routine is implemented correctly. It is far from the most exciting of jobs to back up a computer system but it is absolutely vital if the organisation is to rely on the system.
How often the organisation needs to back up files will obviously depend on the type of data being held. There is a standard procedure for backing up and this is often referred to as the grandfather, father and son, i.e. generations of files. This means that three versions of files will be held; the son which is the current file will be held on immediate storage while the father and grandfather, earlier versions of the files, will be stored in a fie-proof, flood-proof safe.
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