I Have No Mouth, and I Must Scream

The story takes place 109 years after the complete destruction of human civilization. The Cold War had escalated into a world war, fought mainly between China, Russia, and the United States. As the war progressed, the three warring nations each created a super-computer capable of running the war more efficiently than humans.
The machines are each referred to as “AM,” which originally stood for “Allied Mastercomputer,” and then was later called “Adaptive Manipulator.” Finally, “AM” stands for "Aggressive Menace". One day, one of the three computers becomes self aware, and promptly absorbs the other two, thus taking control of the entire war. It carries out campaigns of mass genocide, killing off all but four men and one woman.
The survivors live together underground in an endless complex, the only habitable place left. The master computer harbors an immeasurable hatred for the group and spends every available moment torturing them. AM has not only managed to keep the humans from taking their own lives, but has made them virtually immortal…