What came first, Tron the movie, or Tron the game

[Hoagie_one]

Was one based on teh other?

[JoyMonkey]

Mame's history.dat says this:

Tron (c) 05/1982 Bally Midway.
Based on scenes from the Walt Disney movie of the same name...

[GGKoul]

The movie

[ErikRuud]

They were sort of created together.  The movie concept came first.

They developed the game while the movie was being filmed. 

I beleive the game actually was released before the movie.

The stage of game with the Grid Bugs was based on a scene that ultimately did not make it into the film.  In the final cut they only used one very brief shot of the Grid Bugs, but the rest of the scene was cut.

Here is what KLOV says:
Trivia
The game that became Discs Of Tron was supposed to be included in Tron, but the programming was not completed in time.
As every good Tron fan knows, the grid bugs were almost entirely edited out of the movie (what was left was about two seconds of an animation of a grid bug creating itself). Grid bugs appear in the game because of pressures to develop the arcade game in time for the release of the movie (all part of Disney's sales strategy for the movie's launch -- posters and trailers ended with a tagline along the lines of: "See the movie. Play the game.") So, game programmers had to use whatever script elements they could from the movie before the film itself was actually completed. Light cycles, tanks, recognizers, and the MCP, of course, all made the final cut -- the grid bugs did not.

[Harry Potter]

Tron the egg.

[ErikRuud]

Discs of Tron was originally supposed to be part of the first Tron game, but the programmers fell behind, and it was released later as a seperate game.

[Gunstar Hero]

The game was out first (due to movie delays) but was based on early scenes from the movie, hence the included/fabled/deleted "grid bugs" scene. IIRC, there were even some flyers/posters sent out hyping the game as "Based on the upcoming blockbuster from Disney, TRON."

And DoT was supposed be be included but ended up being expanded into it's own game (despite the failure of the movie at the box office) because the TRON arcade game was SO successful!