How the Apollo Guidance Computer pioneered an era of reliable software

Half a century ago, on 20 July 1969, Neil Armstrong was in the final stages of the lunar descent, just a few thousand feet above the surface, when suddenly his on-board computer indicated a critical alarm. For three nail-biting seconds it looked as if the mission would have to be aborted. However, Armstrong was given a "go" to continue, and after several more alarms the Eagle touched down safely on the Moon.

Robert Wills will introduce the amazing hardware and software that made up the Apollo Guidance Computer, walk you through the landing procedure step-by-step, and talk about the pioneering design principles that were used to make the landing software robust against any failure. He will also explain the problems that occurred during the Apollo 11 landing, and show you how the Apollo Guidance Computer played its part in saving the mission.

Robert Wills works as an engineer for Cisco in Harpenden, writing software for the highly reliable routers that form the core of the internet. In his spare time, he has a keen interest in the history of computing, and particularly enjoys talking about how computers were actually used, the users and the technical aspects. He has been fascinated by the Apollo Guidance Computer for ten years, and is still learning new things about this extraordinary machine.