Category: Old National 5

National 5 – Calculations

  • Size of bitmap = no. of Horizontal pixels X no. of Vertical pixels X Colour Depth
  • No. of pixels = DPI X size in inches

You should also be able to convert from bits, Bytes, Kilobytes, Megabytes, Gigabytes & Terabytes.

  • Bit= 1/0 (Binary digIT)
  • 1 Byte = 8 Bits
  • 1 Kilobytes= 1024 Bytes  (210)
  • 1 Megabytes= 1024 KB  (220)
  • 1 Gigabytes = 1024 MB  (230)
  • 1 Terabytes = 1024 GB  (240)

For colour depth

  • 8 bits = 256 colours (28)
  • 16 bits = High Colour 65,536 colours (216)
  • 24 bits = True Colour 16,777,216 colours (224)

N5 – Technical implementation (storage)

Some of you were concerned that I had missed something that was on your revision sheets, so I thought I might revisit it here. In the previous post I had decided to reorganise this section, which wasn’t reflected in the CAS.

Description and exemplification of the appropriate type of storage required for a specific information system including:

Type of device

It is important to pair the correct type of device with a specific information system. Systems that require a lot of storage like video or image libraries often prioritise this over very fast access to a hard drive is used. While systems that require fast access like video editing will make use of solid state devices.

Capacity

The rule of thumb with capacity is bigger is better, however, this can come at a substantial cost. It is therefore important to understand the needs of the IS, a server will require subtancialy more capacity than a presentation for example.

Interface type

Portable Information Systems will require USB ports to connect to. Some IS devices may make use of wirelesss connections. The computer must have the same interface as the IS device.

N5 – Coding

Description and identification of coding to create and modify information systems including JavaScript mouse events.

Javascript is used in HTML documents to add interactivity. The HTML file below has a number of interactive elements to it. Use notepad++ to investigate it further.

<!DOCTYPE html>
<html>
<head>
<title> Teacher Example  </title>
<!--     
The <script> in the <head> tag allows the functions to be called from 
anywhere in the document
-->
<script>

<!-- Changes Style on Mouse Over -->
function mouseOver() {
document.getElementById("demo").style.color = "red";
}

<!-- Changes Style back after Mouse Over -->
function mouseOut() {
document.getElementById("demo").style.color = "black";
}
<!-- Asks for and displays a name -->
function myFunction() {
<!-- Asks the user to enter their name -->
    var person = prompt("Please enter your name", "Harry Potter");
	<!-- Displays the persons name in ID demo3 -->
    if (person != null) {
        document.getElementById("demo3").innerHTML =
        "Hello " + person + "! How are you today?";
    }
}
</script>

</head>

<body>
<!-- Display a heading that can be changed later -->
<h1 id="demo" onmouseover="mouseOver()" onmouseout="mouseOut()">Welcome</h1>

<!-- Displays a button that when pressed will display the date in the first Heading-->
<p>
<button type="button"
onclick="document.getElementById('demo').innerHTML = Date()">
Click me to display Date and Time.</button>

<!-- Uses Javascript to display the message "Your Text Here" -->
<p>
<script>
document.write("Your Text Here");
</script>

<!-- The text RESULT is not displayed as it is replaced by 
     the results of the calculation below it-->
<h1 id="demo2">RESULT</h1>
<script>
var price1 = 5;
var price2 = 6;
var total = price1 + price2;
document.getElementById("demo2").innerHTML =
"The total is: " + total;
</script>

<!-- This button calls the function myFunction from above -->
<p>Click the button to demonstrate the prompt box.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo3"></p>

</body>
</html>

Description, exemplification and implementation of coding to create and modify information system including the use of HTML with the tags for:
o Document
o Links
o Graphics

The documents below show a HTML document with the basic html document tags and a document showing the html tags for links and images 

<!DOCTYPE html>
<html>
<head>
<title> </title>
</head>
<body>

</body>
</html>

<!DOCTYPE html>
<html>
<head>
<title> Page1 </title>
</head>
<body>
<h1>Example of a heading of type 1</h1>

<h2>And this is heading 2</h2>

<!-- The anchor tag <a> is used to link a html document to another document. 
     The href attribute gives the name of the destination of the link. -->
<p>Here is a paragraph of text,
which includes a link to <a href="page2.html">page 2</a></p>

<p>
<!-- The image tag <img> is used to display an image.
     The src attribute is the name of the image -->
<image src="logo.png">

</body>
</html>

Technical Implementation (software requirements)

operating system platform required  
An Operating system is required to allow all parts of a computer system to communicate with each other and with the user.
Describe the purpose of an operating system including:  
controlling peripherals  
The OS controls the Input and Output to attached peripherals using device drivers.
running software  
The OS schedules software access to the processor, this allows several pieces of software to appear to run at the same time. Example Word-processing while listening to music.
HCI  
The Human Computer Interface is how the user and the operating system communicate with each other. The two main types of HCI are command line where the user types command and graphical where the user runs applications and command using icons and a pointing device.
Understand the features of web browsers including:  
OS support  
Web browsers are often available for different operating systems. This allows the for the same browser experience on different platforms.
privacy modes  
Most modern browsers have a privacy mode that clears browsing history and downloads from the computer at the end of the session. This is useful if you are trying to buy a gift and want it not to show up in your browser history.
Ad filtering  
Browsers have the ability to block adverts, this can either be in the form of a pop up blocker or an extension that removes adverts from the pages. This might cause problems in the future as websites are ran by companies who need to make a profit to pay for the website.
page zooming  
Some people require fonts etc. to be a little bit bigger to make them easier to read. Web pages can therefore be zoomed to increase the size of hard to read content.
Description and exemplification of the appropriate type of software required for a specific information system including:  
type of application  
Word processor, spreadsheet, database, multimedia, presentation, web page authoring software, games.
operating system  
Before buying or using an application you need to make sure that it is compatible with the operating system used on the computer.

N5 – Technical implementation (networking/ connectivity)

stand-alone or networked
A stand-alone computer is not connected to any other computer.

A network computer is connected to other computers via a network, this can be either wireless or wired
LAN/internet
Local Area Network – This a network of computer in a small geographical area, such as a building.

Internet – This is a worldwide network of computer networks.
Description and comparison of the following transmission media in relation to data speeds and ease of use:
wired
A wired network connect is fast connection, which makes use of copper cables to connect to other network devices. This type of network is used for LANs as it has a short range.
optical
Optical networks use fibre optic cables to connect devices together. The data is transmitted as a series of light pulses. Different colours can be sent of the same cable allowing for more than one piece of data to be transmitted at once. Optical networks have the largest range and are often used in undersea cables.
wireless
Wireless networks allow network data to be transmitted without a dedicated wire. The most common are Wi-Fi and Bluetooth. Wi-Fi has the largest range and fasted speed but Bluetooth is the most energy efficient.
Description and exemplification of hardware required for network connectivity including:
Network Interface Card
A NIC is used to connect a device to the network, these can be wired or wireless. The NIC makes sure that the device’s data is

Wireless NICs are often in the form of a USB dongle that can be plugged into any computer or device.
Router
A network router is used to connect one network to another. We use routers to connect our house networks to the Internet. Home routers often have Wi-Fi built in as well as a network switch.
Hub
A network hub is used to connect computers together in a network. Hubs are used in star networks where all the clients share the same bandwidth.
Switch
A network switch is used to connect computers together in a network. Switches have high bandwidth and each device has a direct switched connection to each other.
Description and exemplification of the appropriate type of network connection required for a specific information system including:
Hardware
To connect two or more computers in the network you would need.

·         A NIC for each computer

·         A network hub or switch

·         Cables for a wired network.
transmission media
Transmission media is the connection between two network devices.

·         Wi-Fi & Bluetooth – Wireless radio signals

·         Optical – Fibre optical cables

·         Twisted Pair – Copper cables that are twisted around each and plug into NICs

N5 – Technical implementation (storage)

Comparison of local versus cloud storage  
Since the contents of RAM is lost when power is disconnected it needs to be stored, so it can be used latter.

Local storage is used to store the information on the computer, such as a hard drive or flash drive.

Cloud storage, stores the information on the Internet where it can downloaded and used later.
Comparison of built-in versus portable storage  
Built in storage is fixed inside the computer and cannot be removed. This is normally a Hard Drive or Solid State Drive.

Portable storage can be moved between computer systems, to allow data to be transferred. E.g. Optical Disc, portable hard drive or flash drive.
Comparison of different interface types and their data transfer speeds including:  
Firewire  
This is a wired interface that can connect a device to the computer at speeds of up to 800Mbps. This is often used for portable hard drives or digital video cameras. Devices can be daisy chained together so that up to 63 peripherals can be connected.
USB  
Universal Serial Bus is a wired interface that can connect a device to a computer at speeds of up to 7.2Gbps. A USB hub is used to connect many devices together up to 127 devices can be connected together. Many different devices can be connected via USB including Keyboards, flash drives and mobile phones.
Bandwidth  
Bandwidth is the amount the data that can transferred in a fixed amount of time. This is often expressed in bits per second (bps). A high bandwidth connection is often referred to as broadband.
Description of different types of storage devices and their media in terms of functionality, speed and capacity (in appropriate units) including:  
magnetic  
Hard disk drives are an example of magnetic storage. These random access devices are used to store large amounts of data, 10TB disks are available. Although they can be portable, they are quite fragile and need to be handled with care.
optical  
CDs, DVDs & Blu-Ray are example of optical storage. The information is stored on a disc and read using a laser. The discs are portable but the drives themselves are very sensitive to vibration and can only be used in fixed location. Optical discs can store up to 50GB on one disc.
rewritable, read-only  
Optical discs are available in many configuration and are often suffixed with;

-ROM – Can only be read and not written to.

-R – Is a recordable disc which can be written to once and read many times

-RW – ReWritable discs can be written to many times
solid state  
A solid-state drives have the fastest access and transfer times of any storage device. SSDs are portable in the form of flash drives and are very robust. They are however quite expensive and cannot currently store as much as a hard drive.
Description and exemplification of the appropriate type of storage required for a specific information system including: type of device, capacity & interface type  
Server Based
Servers require fast, cheap storage with a large capacity. As a result, Hard Disk Drives are used. This allows the most amount of storage with the cheapest cost.
Backup
Optical Discs are often used to backup information. As these discs, can be stored securely in a different place from the computer.
On the move
Solid State Flash Drives are very portable with a large storage capacity. These are robust and not susceptible to damage from vibration.

N5 – Technical Implementation (hardware requirements)

Description and exemplification of the appropriate type of hardware required for a specific information system including:
input and output devices
A device which is used to enter information in to a computer system is called a input device. E.g. Keyboard, microphone, mouse, etc.

A device which the processor can send data to or display data on is an output device. E.g. Speakers, monitor, printer, projector, etc.

Some devices are both input and output devices. Touch screen, rumble controller.
processor type and speed (Hz)
Some processors are better suited to certain tasks. So a processor that uses less power might be better suited for a mobile phone or laptop.

In general, the faster the processor the more power it requires, so mobile processors often run a slow speed to desktop processors.
memory (RAM, ROM)
The more memory a computer has the more things it can do at the same time.

More memory requires more power, so mobile computers often have less RAM and ROM than desktop computers.
memory capacity (RAM)
Computer memory is measure in GB. Often computers don’t have the maximum amount of memory installed, this is often due to the costs involved.

N5 – Low-level operations and computer architecture

Explanation of the need to translate high-level program code to binary (machine code).  
Computers can only understand binary code, therefore all human readable programming codes have to be translated into binary. Binary code which contains machine specific instructions is called machine code. A machine code file will only work on the computer type it was created for. Therefore one program does not work on different systems (X Box and Play Station)
Comparison of interpreters and compilers.  
Interpreters – These are resident in the computer’s memory when the program is executed. These translate the source code (program) one line at a time into machine code, this can make them appear slow. Syntax errors are often highlighted as they are made.

Compilers – These translate the source code into machine code, this machine code can then be saved and executed without further need for the compiler. Making the program appear to execute faster than the interpreted version. Syntax errors are only apparent at run time.
Description and exemplification of the use of binary to represent positive integers.  
Binary is a base 2 numbering systems where every digit can have two values ( 0 / 1 )

This is because computers can only represent information using electricity which is either on (1) or off (0)
Conversion from Binary to decimal and vice-versa.  
To convert a decimal number to a binary number, we need to start at 1 and double it.

128 64 32 16 8 4 2 1
0 0 1 0 1 0 1 0

So the number above is 42 ( 32+8+2)
Description of floating point representation of real numbers using the terms mantissa and exponent.  
Binary can only store a whole number so to store a real number we use floating point notation. MxBe. The Base is 2 for binary.

The Mantissa stores the number itself and therefore controlling the accuracy.

The Exponent store the magnitude of the number and therefore controls the range.

Mantissa Range Exponent Accuracy (MARE)
Description of ASCII code (7-bit) used to represent characters.  
American Standard Code for Information Interchange.

Every letter is given a number (A = 65) this is then stored as binary. This allows us to store 128 different symbols and commands, this allows for messages and documents to be read by different computer systems. The 1st 32 numbers are reserved for non-printing characters, such as TAB and RETURN.
Description of the vector graphics method of graphic representation.  
Vector Graphics store pictures as a series of objects and their attributes.

To draw a red circle we would need a circle object and then describe it with attributes.

<circle cx=”50″ cy=”50″ r=”40″ stroke=”black” stroke-width=”3″ fill=”red” />

This is very useful for storing non-photographic work as it can be scaled up without losing quality.
Description of the bit-mapped method of graphics representation.  
Bitmap graphics store images as a grid of pixels (Picture Elements). These pixels values can be changed to display an image. Bitmaps can require a large amount of storage, especially when using colour. The greater the number of pixels the higher the resolution therefor the larger the file size.
Describe the purpose of the Basic computer architecture components and how they are linked together including:  
processor  
The processor is the part of the computer which execute the program, controlling the hardware and software of the computer system. It is composed of three parts.

Control Unit, Arithmetic and Logic Unit, and Registers

CU, Ah Luv U, Right.
control unit  
This is the part of the processor which controls the execution of the program. It uses a clock pulse to sync all parts of the computer, measured in Hertz (Hz). This is often used to measure the speed of a computer. You would expect a 3GHz computer to be faster than a 1GHz computer.
Arithmetic and Logic Unit (ALU)  
This part of the processor performs calculation and is used to evaluate logical decisions (AND OR NOT)
registers  
This is a temporary storage area inside the processor. It is used to store instructions, memory locations or values currently in use. Resetting a processor will clear these values.
memory  
Computer memory can either be RAM or ROM.

Random Access Memory is used to store the data currently being processed, it is volatile meaning that its contents are lost when the power is turned off.

Read Only Memory is used to store programs or data that cannot be changed, such as the operating system or serial number. Contents are not lost when power is removed.
Units of storage

  • bit
  • Byte
  • KB
  • MB
  • GB
  • TB
  • PB
  

  • bit = Binary Digit (0 or 1)
  • 1 Byte = 8 bits
  • 1 KiloByte = 1024 Bytes
  • 1 MegaByte = 1024 KB
  • 1 GigaByte = 1024 MB
  • 1 TerraByte = 1024 GB
  • 1 PetaByte = 1024 TB

 

  
Data Bus  
This is used to carry data from the processor to peripherals (other parts of the computer) and vice versa. The data bus is therefore a bi-directional bus. A bus is simply a group of wires.
Address Bus  
This is used to carry the location of the data from the processor to memory and peripherals. This is a Unidirectional bus.
Interfaces  
An Interface is a hardware device that compensates for differences between the processor and peripheral devices. For example, sound data is analogue and the interface would need to change it to digital before it could be used. There are a number of common interfaces, which are disused later.