That Blue Square Thing

Syllabus content:
PDF iconUnit 4 Boolean logic content – just this section
Note: this syllabus content is a slightly amended version of the one published freely on the web by AQA. I have made very minor adjustments to remove some content less suitable for students to use and it is presented here simply to allow the children I teach to download a usable copy of the syllabus content. It is copyright AQA and reproduced here simply to make access easier for students. No attempt to claim copyright is being made, although I could have copied the text into my own interpretation...

AQA Computer Science GCSE

This page is up to date for the AQA 8525 syllabus for exams from 2022.

4.2 Computer Systems – Boolean Logic Gates

Boolean Logic Gates are electronic components which can take Boolean inputs and provide an output – again as a Boolean value. Remember, Boolean values are either True or False.

PDF iconLogic Gates – intro slides from class

There are four logic gates you need to know: AND, OR, XOR (the evil one) and NOT (the "easy" one which you'll get wrong more times than you think).

Each logic gate has a truth table that you need to know.

PDF iconTruth tables – an intro on how they work

PDF iconHow logic symbols work – a short intro

PDF iconFour Logic Gates – a slide on each to make notes from

There's also a textbook double page on these, which will help if you get confused or stuck.

PDF iconLogic Gates Textbook – a double page spread with questions

PDF iconA table – can you fill it in correctly?

Truth Table Questions

PDF iconTruth Table Questions

Logic Gates and Circuits

You might have to draw a simple logic circuit diagram in an exam.

PDF iconLogic Expressions – types of question

PDF iconLogic Diagrams – types of question

PDF iconExample logic gates – with images

An alternate way asking this sort of question:

PDF iconBlank gates – another way of asking similar questions

A revision exercise:

PDF iconLogic Quickfire – slides from class

More complex Truth Tables

Truth tables get more complex when you start to do more things to the inputs. And especially when you start to add a third input.

PDF iconSlightly more complex Truth Tables – a set of exercises to work through