Two hundred years of technology have transformed how we talk to each other, share our lives and learn about the world. On Saturday, the Science Museum in London opens Information Age: Six Networks That Changed Our World, a new permanent gallery of more than 800 objects that tell the story of the information revolution.

To mark the event, this week we have been hosting five fantastic Science Museum videos that reveal some of the greatest breakthroughs in the communications era.

The fourth film in the series, “The computer that changed our world”, tells the story of the Leo computer developed with funding from Lyons to track products in its teashops. The machine is now considered to have been the world’s first office computer.