Category Archives: 6. External Sites

1. Computer Systems, Homework, Revision

Quick teaser

I lifed this from the 2011 paper it’s question 13

(b) The computer has a maximum addressable memory of 16 Gigabytes. Its address bus width is 32.
(i) Calculate the width of the data bus.
(ii) State why computers do not come with the maximum addressable memory installed.
(iii) State the effect that adding one new line to the address bus would have on the maximum addressable memory.

I thought it was a very good question. I will post the solution to it tomorrow, feel free to comment with your answer but I don’t want you to copy and paste it from the Marking Instructions above.

Computing Higher

Interfacing Revisited

We went back over interfaces today. After the class I had a look about for another set of powerpoints for you to use as revision. There are others out there, just search for them.

We also looked at wireless PAN devices today such as Bluetooth. Remember future development in peripherals, will still have all the issues of today. So the Interface will be required to connect devices to be machines. USB3.0 and Thunderbolt are two of the new standards that give transfer speeds of 5Gbps and 10Gbps. Some interfaces allow for daisy chaining so one port on a computer can have multiple devices connected to it without a hub (Firewire & Thunderbolt).

Computing Higher

Input and Output Devices

Today’s lesson covered Digital Still and Digital Video cameras as well as Laser and inkjet printers. Here are the Peripheral Revision Notes for this section. I have copied the sections below from them.

I promised you a look at a Paintball gun acting like a inkjet printer well here we go. Remember though that inkjet printers only do a line at a time though

[kml_flashembed movie="http://www.youtube.com/v/fKK933KK6Gg" width="425" height="344" allowfullscreen="true" fvars="fs=1" /]

Digital cameras

A digital camera is one of the fastest ways to use pictures in a computer. There is no overhead in developing film and no need to scan images from a printed copy. Pictures are ready to use right away. Because they can be taken and downloaded to your computer in digital form they are ready to use in presentations or even send in email messages. It is now possible to print at home and achieve photo quality results.
The digital camera looks much like a conventional camera – only there is no film! Digital image data is stored in a memory card inside the camera. Digital photographs are bit maps, made up of thousands or millions of pixels with values to represent image brightness and colour.

Printers

Besides the monitor, printers are probably the next most commonly used output devices. They can be broadly classified as character printers, matrix printers or page printers. Character printers and dot matrix printers are pretty much outdated and have been replaced by affordable and more capable ink jet and laser printers.

Task. Why not look up some of the words from the paragraphs above? Example what is a page printer?