Revision notes, activities, lesson plans, teaching ideas, and other resources for GCSE, A-Level, and IB Computer Science teachers and students.
CommandPoint by Northrop Grumman offers a range of CAD systems for various ...
TriTech Software Systems is a company that specialises in Computer Aided Di...
London Ambulance CAD failure
The 1992 London Ambulance Service CAD failure is probably the most notoriou...
Washington State 911 Failure
A 911 emergency telephone system in Washington State and Oregon shut down f...
London ambulance failure (2017)
A 2017 failure of a London ambulance dispatch system is believed to have le...
Computer Aided Dispatch outage
A 911 system failure left emergency calls unanswered and is said to have co...
Load balancing videos
This short article and the associated video explain 5 load balancing algori...
Intergraph Computer-Aided Dispatch (I/CAD
Intergraph Computer-Aided Dispatch (I/CAD) is a system offering many of the...
Boolean logic worksheet pack
These three Boolean logic worksheets have exam style questions on logic sta...
Click here for recommended AQA A-Level Computer Science textbooks.
This video contains lots of examples of converting binary numbers to decimal numbers, and vice versa. A good revision guide.
Unsigned binary arithmetic
Binary Addition & Overflow
Another excellent video from ComputerPhile with their usual clear explanations and worked examples. This video recaps binary numbers and then explains how to perform binary addition. It also deals with the potential problem of overflow and how it can be handled.
Signed binary using two’s complement
Why we use Two's Complement
This video explains how to represent negative numbers in binary. It explains why we can't use a simple sign bit to represent positive or negative numbers, and then looks at how one's complement solves this problem. Finally it explained how two's complement works and why it is used. Although the beginning of the video goes into a lot of detail, it is useful to understand exactly why two's complement is needed and used.
Numbers with a fractional part
A-Level appendix unit - PG Online
Floating point numbers, adders, D-type flip flops are covered in this free lesson resource unit from PG Online. The presentations and activities are designed for the AQA AS and A-Level courses, but the content is relevant to other A-Level courses too.
A-Level only content
Absolute and relative errors
Normalisation of floating point form