Teach Computing

Revision notes, activities, lesson plans, teaching ideas, and other resources for GCSE, A-Level, and IB Computer Science teachers and students.

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Examples of Local Cryptocurrencies

Digital Money for Local Communities covers three examples of country-wide c...

Hash function A hash function takes arbitrary sized input data (e.g. a fil...

Cryptocurrencies vs regular currencies

What is Bitcoin and How Does it Work? is a high level overview of the Bitco...

Examples of Cryptocurrencies

Bitcoin is by far the most well known cryptocurrency. The Bitcoin website w...

Practice paper 3 exam questions

One of the drawbacks of the yearly case study is that there are no past p...

Emergency Management System Explainer Video

This short video gives an overview of some EMIS features. It includes many ...

Geographic Information Systems (GIS)

For some functionality, an EMIS may also be connected to a GIS (Geographic ...

Programming languages - from Scratch to machine code

The CS Field Guide has a very comprehensive guide to different types of pro...

Assembly language simulators

There are several assembly language simulators available for use online. Si...

Resources discount offer

3.3 Hardware

Click here for recommended Cambridge A-Level Computer Science textbooks.

3.3.1 Logic gates and circuit design


XOR and Half-Adder

This video starts by recapping the truth table for an exclusive-OR (XOR) gate, and then goes on to show how its properties can be used to help create a half-adder in conjunction with an AND gate. The video helps demystify the concept by building up the half-adder and explaining with examples why an additional gate is needed.

Updated: 2015-04-29

3.3.2 Boolean algebra

Boolean expression simplification

Logic Simplification Examples Using Boolean Rules

This is an excellent video which goes clearly through the individual steps of simplifying Boolean expressions. The video starts with a clear list of simplification rules and explains why they work. There are then two examples, complete with logic circuit diagrams, which are worked through line by line until they are fully simplified. This is probably the clearest explanation of Boolean simplification I have seen. (The video is a lot better than the screenshot makes it look!)

Updated: 2015-11-24

3.3.3 Karnaugh Maps

3.3.4 Flip-flops

3.3.5 RISC processors

3.3.6 Parallel processing

CERN Grid Computing

CERN Grid Computing system

This brief tour of the CERN computer grid gives a good overview of the computing system and the power available.

The second video features interviews with CERN employees who explain how the grid computing system works and how the data is transmitted to and processed by multiple tiers of computers spread across Europe.

Updated: 2015-05-27