Category Archives: 6. External Sites

1. Computer Systems, Computing Higher

Introduction to networks

I forgot to set today’s blogger so I will make the post today.

We started topic 5 &6  of computer systems today which is networking. You will find the full contents of the topic at the bottom of the post, these were lifted from the SQA arrangements.

Today’s lesson focused on the need for networks and the desire to share information. A lot of the class was spent discussing the sharing of information offline as well and online. We looked at the need for a Network Interface Card (NIC) and the advantages of central stores of information (Capacity and backup)

Networking
  • Comparison of LANs, WANs, Intranet and Internet work in terms of transmission media, bandwidth, geographical spread and functions
  • Distinction between a mainframe with terminals and a network of computers
  • Descriptive comparison of peer-to-peer networks and client server networks
  • Description of the functions of file, print and web servers
  • Description of a node and a channel
  • Description of bus, star, ring and mesh topologies using the terms node and channel
  • Description of the consequences for each of the above topologies of node and channel failure
  • Simple description of the functions and uses of a hub, switch and router
  • Identification of the need for a network interface card (NIC)
  • Description and explanation of the trends towards higher bandwidth and wireless communications
  • Description of the following technical reasons for the increasingly widespread use of networks:
    • advances in computer hardware, including processors, main memory capacity, backing storage, data transfer rates
    • improved network related software, including browsers and network operating systems
  • Description of the misuse of networks for the following illegal purposes: breaching copyright, hacking and planting viruses
  • Description of the application of the Computer Misuse Act, the Copyright Designs and Patents Act and the Data Protection Act to the misuse of networks
Computing Higher

Getting An Avatar On The Blog

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You may have noticed recently that Mr. Stratton got himself a little avatar that appears when posting in comments.


You may also notice that I, David, have one too.  You may want one of these, so here’s what you have to do…

go to http://en.gravatar.com/

and click here where the red arrow is pointed


When asked to enter an email address, use your Glow mail address, which can be found by visiting Pupil Home on the Glow site, going to the bottom of the page and clicking on “Change Profile”.  A window will appear and your email address will show, like this –

Copy and paste this address into here –

After signing up you will receive a email waiting for you to confirm your want for Gravatar’s service, so go to the Glow Light welcoming page and click on the Envelope Icon –

You will have an Email from Gravatar waiting, read it and follow the confirmation link given.  You will now be given the option to upload an image which will show up whenever you post somewhere on the blog.  As long as it is square it can be any size, as Gravatar will resize the image for you or if you are only wanting part of the image you may crop it yourself.  Good luck and post a comment with your new picture, or not if you can’t do it, if you need help or to show off your new avatar

2. Software Development, Computing Higher, Coursework

Topic 8 Real World Programming

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today we started the topic 8 notes, so far we have been learning the programming side to the software development, but topic 8 is all about the other stages.

The stages of the software development cycle are as follows:

Analysis:-the main purpose of this stage is to be absolutely clear about what the program is supposed to do. We must turn a rough idea of what we want the program to do into a detailed description of how it will behave, by asking questions on what the I/O are, and what type of computer it will run on etc. Through this we create the software specification, agreed on by both the client and the developer. This is a very important document and it is a basis of a contract between the client and the developer. It sets out exactly what the client is paying the developer to produce. It can be used at the end of development to resolve any disputes.

Design:- a lot of people just jump into implementation when giving a task. But you MUST not do this, you need to design the program your going to create. Designing the program before implementaion will make is easier. Create Structured Diagrams, or Pseudocode to make it easier to see what steps are needed to make the program work. In real-world programming a test plan is created before implementation begins. The test plan is based on the software specification.

Implementation:- This is where you change the program design into a programming language. This is done by a team of programmers, a team approach is possible if the code used modular program design. Modular programming allows you to re-use section of pre-tested code.

Advantages of modular programming are:

  • it allows programmers to work indepentandly on different sections of the software.
  • Any modules developed with me well documented for inclusion into a module library for future use.
  • and Sections of the overall software can be tested independantly as their developed, this making tracking and destroying bugs easier.

Testing:- Testing is a vital part of any development process.

their are two types of testing. Systematic and Comprehensive.

Systematic Testing: this means that the testing is planned and structured, rather than just random tests. A test plan is developed during the design stage.

Comprehensive Testing: this means that everything is tested. Every part of every module, and aswell as the whole program. Comprehensive testing inclused testing under Normal, Extreme and Exceptional circumstances. The criteria for passing the test stage will have been laid down in detail in the software specification

Testing Normal Conditions: Making sure the program does what i should do when used “normally”. E.g. a program where you enter a number between 1 and 10. Entering numbers such as 4,5,6 are testing it normally.

Testing Extreme Conditions: Making sure the program can handle situations that are at the edge of what would be considered normal. E.g. the same example above, numbers such as 1 and 10 would be testing the extreme conditions.

Testing Exceptional conditions: making sure it can handle unexpected situations of inputs that its not designed to cope with. E.g. The same example as above, numbers such as 15, -98, 11 are all testing the exceptional conditions.

Documentation:- When you buy a peice of software, their are usually two peices of documentation inside. The user guide, and the technical guide.

The user guide tells you how to use the product, and might also include a tutorial, taking you through the uses of it step by step.

the Technical guide gives you technical information of the product. E.g. The software requirements how much RAM the software needs to run, the OS that it works on and how fast the processor needs to be. It should also contain instructions on how to install the software.

Evaluation:- Evaluation involves reviewing the software under 8 headings. These headings are:

1. Is the program fit for purpose?
2. Is the user interface good to use?
3. Is the program code readable
4. Is the program robust?
5. Is the program reliable?
6. Is the program portable?
7. Is the program efficient?
8. Is the program maintainable?

The definition of all the words in Itallic are all in the software development glossary that you were given out. If you do not have this glossary you can find it here.

THIS IS VERY IMPORTANT FOR THE COURSEWORK!

1. Computer Systems, Computing Higher

Algorithms

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The snow unfortunately has caused problems within the school and lessons have been distrupted but we must get cracking on.

An algorithm is an effective method for solving a problem using a finite sequence of instructions. Algorithms are used for calculation, data processing, and many other fields. The first few examples of a standard algorithm used unconditional loops;

1) Set found flag to false  

 2) Enter item to be found  

3) FOR each item in the list  

4)  IF current item = item to be found THEN

 5)  set Found flag to true

6)  display item and its location

7)  END IF

8.) NEXT item

9) If Found flag = false display “not found” message

This is already in the powerpoint but for those that will not look at it, this is used to find an item on a list. How it works is that it searches through all the list and finds the object that the user was looking for.  The next one we looked at was “COUNTING OCCURENCES”. This algorithm is used to count how many times the value appears on the list which is given.

1) Set the number of times item found (hits) to zero

2) Ask user for item to be found

3) Enter item to be found

4) FOR each item in the list

5)  IF current item = item to be found THEN

6)  add 1 to number of occurrences

7)  END IF 8.NEXT item

8.) Display number of occurrences

Now this is very useful when looking for an object and how many times it appears. The last two ones we looked at were the “MAXIMUM” & “MINIMUM” This is it;

1) Set maximum value to be equal to the first item in list

2) FOR each item in the list

3)  IF current item > maximum value THEN

4)  set maximum value to current item

5)  END IF

6) Next item

7) Display maximum value

This is useful when looking for the largest value. The minimum algorithm is the exact same but MINIMUM is put in place instead of the MAXIMUM. We then went on the computer and used these. Remember and post comments on blogs and look on glow for the helpful information!

P.S I would add photo’s but I have no clue what photo’s I would add to this.

2. Software Development, Computing Higher, Homework

Online resources

Just a reminder that you have access to a large number of resources you can access even if you are not at school.

I have added the powerpoint from today’s lesson to the Glow learn area, I am going to stop add files into the Glow Group and I will convert it to a learning space before the prelim.