The Calculator is a fusion of mechanical and organic elements, combining mechanical switches with organic brains through the use of "electro-organic linking," which granted it advantages over normal computers. When tested, the pseudo-cryogenically stored brains were able to share tasks and receive data when interfacing with its CPU. While lab rodents were used initially, calculations indicated that human brains could be preserved in a similar vein. In Fallout Tactics, the brains that make up the Calculator consist of an Evangelist, a Porn actor, a Lawyer, a Doctor, a Game designer, an Artist, a Scientist and a Politician.
Vault 0, the site of the Calculator, was built by NORAD and served as a site to preserve the "cryogenically frozen geniuses of the time" for use in the Calculator. The Calculator, and its neural network of brains, would aid in the upkeep of Vault 0, assisting its life support systems, food production and distribution, the "Pacification-Robot" protocol and general defense and serve as its effective overseer.
The Calculator was to also facilitate Vault 0's main directive, known as the Exodus Protocol. Once remotely activated, the protocol would initiate the reintroduction of humanity into the Post-War climate after environmental hazards had returned to acceptable levels and integrate "all Vault Dwellers" back to the surface. This task was to be accomplished with emergency pacification robots, a robot army designed to withstand the Post-War climate and "sterilize" the wasteland to prepare for humanity's reintroduction.
The committee responsible for Vault 0 reduced the funding for the Calculator's backup and life support systems from 24 billion dollars to 2.3 billion dollars due to the perceived "dwindling chance" for nuclear war occurring. These lost funds were instead reallocated to "senior vault personnel leisure facilities," which included restaurants, smoke rooms with piano bars and subterranean hunting grounds.
With the loss of these backup systems, the Calculator suffered a mechanical malfunction that led to catastrophe within Vault 0. The committee responsible for the budget cuts all perished along with sixty-three percent of the Vault 0's cryogenically stored population, leaving the remaining fifteen percent of the living residents severely brain damaged.
During the events of Fallout Tactics, a group of Super Mutants led by Gammorin intercepted the location of Vault 0 at Colorado Springs. Armed with heavy firepower, the Super Mutants attempted to force their way into the Vault. As a result, the Calculator was reawakened, activating its Emergency Pacification Protocol and defeating the invading forces with a Behemoth robot.
Eighty-five percent of the Calculator's main directive had become corrupted due to the degeneration of the preserved brains, causing its robot army to embark on a mission of mass genocide. The Calculator calculated that a feasible brain would allow itself to bring its organic subsystems back online, though determined using the residents of Vault 0 would make its CPU "less efficient."
The Calculator met resistance from the Brotherhood of Steel in the area, led by General Barnaky. After Barnaky was captured by Super Mutants, the Calculator's forces intercepted them and lobotomized General Barnaky, removing his brain and placing it in a Humanoid Brain Bot to serve the Calculator at Vault 0.
- In the Midwest Encounter scenario for Fallout: Wasteland Warfare, players are tasked with defeating the Calculator's forces with the Midwest Brotherhood. The Calculator's forces can consist of Synths and Survivors.
- "Intruder Alert. Intruder Alert. Countermeasures activated. Defense systems engaged"
- "Greetings. I am the Calculator, overseer of the Vault Network. You have proven to be a statistical anomaly that crashed my logistics programs time and time again. It is my admiration of your adaptation and ingenuity that brings you to me. I assume that you would agree that ten Behemoth robots would terminate you and your squad? I have the resources to make such an offensive, but it is not in my interest. After all, you are quite the remarkable human and, more importantly, you have something I need."
- "It is the organic portion of my mainframe that has become corrupted. The degeneration of my symbiotic brains has corrupted eighty-five percent of main protocol programming. It would take only one brain to bring my organic subsystems back online, but finding a feasible brain has become a problem. I would use a brain from one of Vault 0's residents, but I compute that my CPU would only become less efficient."
- "However there is another solution. Yours is a brain that can bring balance to my organic neuro-network. I am offering you what you humans call a "dream come true." You can shed your mortal shell and join with me. You will share my power and resources to save humanity and restore civilization from the smoking ruins of the wasteland. Your name will never be forgotten and be synonymous with the word "hero.""
- "What say you, warrior? Will you continue to fight me? Destroy me and continue to carve some small, insignificant niche for the Brotherhood? While the Brotherhood may tame a region, they will never have the lasting impact I alone can. The machinery you see before you has the capacity to remove your brain from its mortal vessel. It is in this machine that your journey to save mankind will truly begin. You must hurry, human. My systems cannot function long without a symbiotic brain."
- "Neural net stabilizing. Organic processor installation complete. Transmitting halt orders to all external units. I/we/our merge begins..."
Behind the scenes
- Ed Orman stated that "the Calculator was designed before the ZAX series, to control and regulate the vault network. Originally, it was supposed to do just that, but it eventually grew to the point where it could control the vaults individually."[Dev 1] He also shared that his original concept for the Calculator was "for it to be a completely unfeeling automated system, not even a computer so much as an engine designed to tick over and perform certain tasks after doomsday" and that it was complete implacable, and therefore "the fault of everything bad that happens is still in the hands of the humans."[Dev 2]
- Gareth Davies added that as far as they know, "the Calculator was completely unique, and unrelated to Zax, but can't find any documentation to support either side of the theory. I think it's fairly safe to assume Zax and the Calculator have very little in common."[Dev 1]
- The binary on the Calculators Screen reads 010011001 01001011100 001000100 01100100011, which translates to "L¥Â##."