Category Archives: 6. External Sites

1. Computer Systems, FAQ, Revision

FAQ – Hub or Switch

Simple description  of the functions  and  uses of a hub, switch and router

  • Hub
    • A Hub is a multi-port repeater. That means that data coming into one port is sent out of all other ports. This can result in congestion on the network as machines are swamped with data that id not for them, resulting in a slow down of network performance. A 100Mbps hub shares this with all machines, so each machine only gets a fraction of the speed.
  • Switch
    • A switch keeps a database of each machine on the network and which port of the switch they are connected to. These collision domains are controlled by the switch, which then results in a reduction of the number of collisions increasing the overall speed of the network. A 100Mbps switch gives each machine 100Mbps.
  • Router
    • A router is a device with two network cards that is responsible for routing data from one network to another. It does this by keeping track of IP addresses of computers on the networks and forwarding packets appropriately.

Remember the warriors of the net video is a good lead in, but look up the terms online.

[kml_flashembed movie="http://www.youtube.com/v/PBWhzz_Gn10" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

Computing Higher, Revision

Games to pass the time

OK so you are past paper’ed out and couldn’t read another paragraph or write another flash card.

Well its quiz time, you can even try and check your glossary skills. Crosswords might be your thing. If you are going to go ofline for a bit then print out some sheets for later.

Quizes are great but they are even better when you learn from them, so keep a note of the ones you get wrong and search for them as part of your study. Build in quizzes to your study or make your own.

Continue reading Games to pass the time →

Computing Higher, NAB, Revision

Question make up

The higher paper is made up of both KU and PS questions, just like the standard grade. If you don’t believe it have a look in a marking scheme.

The image above is taken from the arrangements document, it gives you a list of keywords you can use to identify KU & PS questions. Remember that it is important to answer all questions in the context they were given. So for a question about “surequickfit”, you should mention “surequickfit” in your answer as well as relate to their problem. The breakdown of the assessment is below. Continue reading Question make up →

1. Computer Systems, Computing Higher

Our new PCs

2 Comments

Well I finished setting up the new machines today, and even as I type this, the network should have finished installing software on them and is shutting them down.

I took one of the machines out for a bit of a test to see what it could do, but before I comment on that, lets look at the specs.

  • i5-2400 processor
  • 4GB RAM
  • Windows XP 32bit
  • 512MB GPU (can’t remember the model right now except it was a radeon)

The machines are in a slimline case and look OK for a HP.  I loaded up most of the games that were too slow for my old machines; warsow, world of padman, etc. I set the graphics options to max and had a look at the frames per second – rock solid on 75+FPS, which means they should be fast enough for anything we want to do.

One thing though, the desktops are only reporting 3GB, why is that and what can we do about it?

Computing Higher, Revision

Newspaper Exam Guides

Well the Sunday papers have all had a exam guide or two in them. If you missed them then ask about, you might find an aunt or uncle keeping a copy “just in case”

A few of these have been published online over the past few years, but remember before you go searching the net for them, that the computing exam changed in 2005 (other subjects may have changed as well), so be careful to get the right one. I have one or two copies in school and found this one in Dundee.

1. Computer Systems, Computing Higher

Password Security

I found this image on the net and I would have endorsed it whole heartily in the past but my choice of passwords has changed recently.

(c) zonealarm

One of the reasons for making passwords cryptic was to stop the casual observer keyboard watching your password. Now though we tend to use our own machine so the need to protect against observers has lessened. However recent GPU based password crackers have rendered this method of password creation virtually obsolete, so we need a new way to remember passwords.

We are no longer limited to 8 character passwords (can you guess why the limit was 8?), so we could use a sentence. The chances are though, there will be password dictionary based on song lyrics or movie quotes along any day now and Artificial Intelligence might make a good stab at these in the future. So we need a way of remembering passwords that are strong and hard to brute force. I found this image that conveys this perfectly.

(c) XKCD.com

So the next time Facebook or Glow asks you to create a password, try and think outside the box.

REMEMBER attempting to access someone else’s account is illegal and a breach of the Computer misuse act in the UK. The Internet makes it easy to access computers around the world and some countries have more severe penalties.