A Space Invaders animation written for the Edsac simulator.
I wrote this in 1999 for a History of Computing assignment whilst in the final year of my Computer Science degree at the Universty or Warwick.
I'm pretty sure I understood it at the time, but the course lecturer was right, I needed more comments in my code.
Wikipedia has this to say about Edsac:
The electronic delay storage automatic calculator (EDSAC) was an early British computer. Inspired by John von Neumann's seminal First Draft of a Report on the EDVAC, the machine was constructed by Maurice Wilkes and his team at the University of Cambridge Mathematical Laboratory in England. EDSAC was the second electronic digital stored-program computer to go into regular service.