Colossus - The Forbin Project

Aroview: Believably unsettling cold war parable concerning a huge electronic brain called Colossus, designed to control the American missile defense system.

Communicating with its Russian counterpart, Colossus develops an intelligence of its own, and decides to take over the Earth, threatening global destruction should anyone try to pull its plug. Well-directed and under-appreciated, and something of a progenitor to a 70's mini-genre where computers run amok.