Credit: Tron: The Everett Collection

Back in the primordial mists of the late 1970s, topflight computer animation basically looked like a Colorforms play set: What it rendered best was brightly hued geometric shapes. But writer-director Steven Lisberger came up with an ingenious way to exploit the limitations. Working in the last, desperate days of Disney’s pre?Michael Eisner era, he sold the studio on making a cyberthriller about a programmer (Jeff Bridges) sucked inside a sterile, gleaming, partially CG-rendered computer world to do battle with the corporate creep (David Warner) who stole his best work. Despite some beautiful imagery, supervised by longtime Disney effects wizard Harrison Ellenshaw, Tron was never more than a white-elephant curio upon its release. It founders due to dull supporting players (Bruce Boxleitner, wake up!) and weak plotting, and now that the world has seen ”The Matrix,” it’s an outright relic. Still, this deluxe double disc, filled out with extended testimony from the filmmakers and such boosters as Pixar’s John Lasseter (who says ”without Tron there would be no Toy Story”), makes for an engaging requiem. Add a half grade if geek-lingo insults like ”bit-brain” make you smile. Infomerciality alert: The supplements contain pointed tub-thumpers for a possible sequel, ”Tron 2.0.”