Tron (20th Anniversary Collector's Edition) [DVD]Set Contains: A new 90 minute documentary on the origins and making of Tron anchors this two disc, 20th anniversary set, and does a good job of showing the remarkable odds the filmmakers faced. The 15 minutes of computer graphics in the film were developed when this science was in the infant stages; programming often came down to punching numbers into a spreadsheet. Many fans will be surprised to learn how much of the film relies on backlight