WarGames (1983), directed by John Badham.
A high school hacker looking for unreleased computer games mistakenly finds a backdoor into North American missile defense. He starts a game of "Global Thermonuclear War" which becomes pretty tense pretty quickly. Realizing his mistake he tries to shut it down, but the computer takes its games seriously. Unstoppable countdown to WW3...
It's slickly written, moves along nicely and is still a lot of fun, if rather light. Given recent history, the notion that military computers can be hacked by kids is more believable now than it was at the time.
The Cold War still had years to run when this wry teen-romance entry in the gut-wrenching-threat-of-nuclear-war genre was made, which is pretty bold. I'm not sure they ever got credit for that. Adding a more adult, emotional dimension: the grief and cynicism of Dr Falken, with the war computer as a surrogate for his lost son.
The second climax in the war room when the computer plays hundreds of nuclear war simulations, looking for a solution, is really stunning. I always thought those big screens were done as post-production opticals, but no: each screen had a film projector behind it.
Second film for both Matthew Broderick and Ally Sheedy. I always like seeing John Wood (Dr Falken) and Barry Corbin (General Beringer).
Misc notes:
Apple and IBM had begun mass-market home PCs by the time this film was made, but the kid has older generation gear: that brief silver age when cheap computers were kit-based and you needed considerable skills to get them working.
See his acoustic coupler? Nobody misses those. Likewise for the 8" floppies: their drives sounded like a piano rolling down the stairs.
An office gag we used to do: point your finger and say, "Turn the key, sir! That's not the procedure! Turn the key, sir!"
The kid gives the computer a voice, but we continue to hear it even when we are away from his gear. Maybe we are supposed to understand this is imaginary, not audible to the characters. The writers said "The audience won't care".
The voice is an electric Dr Falken, a nice touch.
Sparks flying out of stressed computers is a bit of 1960s dumbness.
Available on Blu-ray. A pleasant commentary track with the director and two writers gives production details and good insight into the overall design of the screenplay. Made in 1998 it is a bit of a time capsule itself: their comments on dated technology reference their own now-dated technology.