The video here has a lot of information. If you're short on time, I recommend watching the simulation of how the system would assign and deploy fighter jets and surface to air missiles to each threat, which is at about the 20 minute mark.
Dag Spicer from the Computer History Museum leaned over and unscrewed a bolt. Underneath, it read, "I can't stand it". The operator's job was to look for cold war bombers that never came. I would go mad, too. Look: