This revision booklet covers all the specs, taken from slides created by OCR that I have used at school. This will be useful if you are re-sitting the F451 exam from last year. Please note this is not for the new Computing h046 h0446 which took effect in September 2015. However it will most likely contain information which is still relevant. In addition, some extra details may not be in the document as they were not in the slides. I would recommend still going over past papers (type h047 in your web browser) as well to get a better understanding of what the examiner wants. Finally, some of the information of changed as the slides which were used are quite old. For example with the definition of an Interrupt has changed from a message to a signal. I hope you find this useful, apologies as the exam is very near.