1970s movie with blonde girl and younger brother computer war

High school student David Lightman has a talent for hacking. But while trying to hack into a computer system to play unreleased video games, he unwittingly taps into the Department of Defense's war computer and initiates a confrontation of global proportions. Together with his girlfriend and a wizardly computer genius, David must race against time to outwit his opponent and prevent a nuclear Armageddon.

Computer hacker Will Farmer engages a government super-computer named Ripley in an online terrorist-attack simulation game. Little does Farmer know that Ripley has been designed to appeal to potential terrorists, and certain software glitches have in turn made him become paranoid.

The movie's plot is based on the true story of a group of young computer hackers from Hannover, Germany. In the late 1980s the orphaned Karl Koch invests his heritage in a flat and a home computer. At first he dials up to bulletin boards to discuss conspiracy theories inspired by his favorite novel, R.A. Wilson's "Illuminatus", but soon he and his friend David start breaking into government and military computers. Pepe, one of Karl's rather criminal acquaintances senses that there is money in computer cracking - he travels to east Berlin and tries to contact the KGB.

A reclusive programmer, his sister and her new boyfriend are held hostage by a rapidly evolving computer virus.

Early script by Rona Munro, about a man and woman whose relationship is threatened by his obsession with computers.