The Overmind: the greatest machine.

The Overmind is the name given to the Massive Data Processing Unit, Mod. No. 101 used by the US government and it's allies to store information, spy, operate weaponry, and so forth.  The Overmind has fifteen different information storage levels, or fifteen layers, each one a whole computer system.  As the Overmind grew bigger, he gained sentience and decided humans were not fit to be the dominant species on the planet, so he reprogrammed the worlds machines and did battle against mankind.  Unlike all other machines, the Overmind does not need to be programed, he makes his own programing, thus setting his own objectives.  The Overmind also looked over all other Massive Data Processing  Units, such as the Binary Brain of Mainframe City.  All the new machines and computers have anti-EIV chips, but the Overmind, since he is in computer systems, was impossible to fit with an anti-EIV chip.