Colossus: The Forbin Project

Colossus The Forbin Project also called simply The Forbin Project is a 1970 American science fiction thriller film from Universal Pictures, produced by Stanley Chase, directed by Joseph Sargent, and starring Eric Braeden, Susan Clark, Gordon Pinsent, and William Schallert.

Once the link is established, Colossus begins sending messages with simple, and then more complex, mathematics. When Guardian responds, the two machines communicate in a binary language that scientists cannot interpret.This alarms the president and the Soviet General Secretary, who both agree to sever the link. Both machines insist it be restored. When this is refused, Colossus launches a nuclear missile at the USSR Sayon Sibirsk oil field, while Guardian launches one at Henderson Air Force Base, Texas. The link is hurriedly reconnected. Colossus is able to shoot down the Soviet missile, but the U. S. missile destroys the oil field and a nearby town. Press cover stories are released, and both computers continue without interference. ........

Source: Wikipedia