Category Archives: 1. Computer Systems

8 bit computing

Some of you have built your own computer. Well, you have assembled the pre-made parts, but before the PC all the parts had to be soldered together. This article shows how an eight bit machine could be made today.

I have never assembled a complete computer this way, however, I have used pic microcontrolers to make some projects. Tutorials like this one can be found using Google.

If it all feels a bit like hard work then there are a range of small cheap hobbyist PCs like the pogoplug which have a large on-line community to help you get started. Remember computers are not all about games and the Internet, take the subject of control for example, which leads you on to home automation.

Animated GIFs

“Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways.” – Wikipedia

The software used today was Styks. It allowed us to create an animation using GIF.  I asked you to save it as GIF as this is a common file format that can be edited with ease in other programs.

Most of the class then discovered that Fireworks could be used to edit the GIF and re-save it. There are other packages that allow you to edit an animated GIF, have a look for some freeware examples.

If you managed to do this then please post a blog of your finished artwork.

Computer Graphics

Well Crysis 2 is out and it gives me a chance to talk some more about resolution and graphic quality. The video below shows the same levels on a PC and 360. The video has been captured in HD from both sources and can be best seen if maximised to full screen (make sure to turn up the quality to see the differences). Pay attention not just to the level of detail on both platforms but also to the background, everything in a game needs to be rendered in real time by the CPU & GPU. Could it be that the 360 is starting to show its age?

WARNING Youtube videos, comments and posts often contain unsuitable language and material that may be age sensitive. They are out with the school’s control and should be viewed with caution.

[kml_flashembed movie="http://www.youtube.com/v/7Gj6fgnMvQw" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

How Stuff Works!

I was using Stumble Upon tonight when I came across the this site explaining how caching works.

It has a good explanation of how a cache works but the rest of the site is a little goldmine of videos and explanations. Take for example part of Tuesday’s lesson on scanners or Wednesday’s image type lesson.

When you are creating blog posts of lessons in the future, use the tools at your fingertips and search and research the topic more, rather than just relying on what you remembered from the day. Take this video as an example

WARNING Youtube videos, comments and posts often contain unsuitable language and material that may be age sensitive. They are out with the school’s control and should be viewed with caution.

[kml_flashembed movie=”http://www.youtube.com/v/vJG698U2Mvo” width=”425″ height=”344″ allowfullscreen=”true” fvars=”fs=1″ /]

A lesson is a lot like that, you will pick the bits that you think are important but you need to remember that there is a lot in there you must read up on later.

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

Algorithms

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.

Coursework – good and bad

The lesson today was the first in over 2 weeks. We have had very bad snow in Scotland and this has resulted in a lot of missed work. The class were reminded about Scholar, Glow and other resources.

The class was sorted into friendship pairs and I issued sample coursework to the pairs. One half of the room had candidate 2 and the other candidate 3. The pairs were to discuss the coursework given out and look at the example to find out if it was a good or poor candidate. Both example students had passed the coursework task when it was given but one had scrapped a pass and the other had achieved 58/60. We swapped sheets and took notes about what is expected during the coursework.

The class has had some problems with glow so we undertook a sample homework assessment to make sure that the class could submit the homework for Tuesday on time. Scott Brown scored full marks in the sample homework.

Homework will be posted in Glow tonight.