Colossus: The Forbin Project

Thinking this will prevent war, the US government gives an impenetrable supercomputer total control over launching nuclear missiles. But what the computer does with the power is unimaginable to its creators.

Colossus: The Forbin Project is a 1970 thriller sci-fi movie directed by Joseph Sargent, starring Eric Braeden, Susan Clark, Gordon Pinsent. It holds an IMDb rating of 7.1/10 from 11,613 votes and runs 1h 40m.