The Mainframe is the name of the base that the teleporters are linked to and appear in Der Riese, Kino der Toten, Moon, The Giant and Revelations. They can only be activated after the power has been turned on except in Moon. After a teleporter is used, all players who used it will return to the
mainframe. In Der Riese and The Giant, the mainframe is in the courtyard where you first spawn and in Kino der Toten it is located in the lobby where you first spawn. The teleporter in Kino der Toten needs to be linked to the mainframe before each use. The teleportation system also has to cool down after each use, which takes approximately two minutes. Also in Kino der Toten, after using the teleporter, the player will be sent to the Pack-A-Punch room for thirty seconds. Once these thirty seconds are up the player is sent to the mainframe. The player might also be sent to one of the random rooms, which may contain a film reel and/or a power-up. After about five seconds, the player is teleported to the mainframe.
The mainframe is active when the power is turned on. Players can use it as many times as they want on Der Riese, but will have to re-link the mainframe with the teleporter in Kino der Toten after every use.
- A mainframe can be seen behind a window in the zombie map "Five". This is explained by a piece of intel that says all Wunderwaffe projects were to be sent to American-controlled facilities.
- Evidence given in the Moon radio's suggest that at one point, either Mainframes or teleporters had a lock on mechanism to teleport targets even if they weren't on a teleporter. This is revealed when Dr. Maxis was teleported to the moon by Groph while he was in a tunnel.