Logic Gate Expressions

This computer science video follows on from the video about combining logic gates. It covers how a logic gate diagram can be described with a Boolean expression. This includes how to come up with a valid expression for a given combination of logic gates and, conversely, how to draw a logic gate diagram for a given expression. The order of precedence of the logical operations NOT, AND and OR, and the importance of brackets, are also discussed. It was the British born mathematician George Boole who in the mid 19th century, long before digital computers were even dreamt of, first described complex logical arguments using algebraic expressions that could be manipulated and simplified. Almost 70 years later, the American mathematician and electrical engineer Claude Shannon, showed that ‘Boolean algebra’ could be applied to the design of switching circuits; circuits that effectively handled binary ones and zeros. It was the work of these men that laid the foundations for the invention of the modern digital computer, and this video will give you some insight into how their work came together. This video also sets the scene for learning the rules of Boolean algebra, a very powerful tool for computer circuit design.