Fascinating documentary contained on the Tron 20th Anniversary 2-DVD Special Edition in which you learn the long road Steven Lisberger and his company took to make Tron, from their early work in backlit animation to the tumultuous story of Animalympics to how they convinced post-Walt Disney/pre-The Little Mermaid Disney to back a cutting edge, decidely un-Disney like production.
A box-office failure in 1982, the documentary also discusses how kids who were 10 to 14 years old at the time latched onto it. It's also interesting to note how much Tron fortold - even being arguably the first cyberpunk movie, since it features the earliest reference to hacking and the world of Tron itself is the first depiction of cyberspace.