Calculator

The Calculator operates Vault 0, designed to facilitate humanity's reemergence into post-nuclear America.

Background
To coordinate the effort and control the functioning of the vault, the Calculator was created as an advanced supercomputer using an electro-organic terminal to link its central processing unit to the brain stored in pseudo-cryonic conditions, fed specifically formulated nutrients to sustain suspended life. This was intended to assist the Calculator in vault management, including life support, food production and distribution, pacification robot protocol, and defenses. Ultimately, it would also aid in executing the Exodus Protocol when outside temperatures, radiation levels, and poison particle counts returned to normal. It was also programmed to finish the construction of the Hellion, a prototype battle airship.

Before the Great War broke out, the committee responsible for managing the construction of Vault 0 reduced the sum allocated for computer backup systems from 24 billion dollars to 2.3 billion, to cover pay increases of senior committee members. During and after the war, the Calculator survived, undamaged under Cheyenne Mountain alongside other robots and humans in cryogenic suspension. When a group of super mutants from Gammorin's forces breached Vault 0's perimeter, the Emergency Pacification Protocol was activated. It was designed as a contingency in the event of substantial foreign military presence, dangerous mutations or breach in the Vault's defenses. The Calculator released a robot known as the Behemoth to eradicate the invaders.

Due to the pre-War budget cuts, the Calculator's functions were impaired and the electro-organic linking terminal was damaged, resulting in 63% of the vault population's deaths, including First Scientist Napstarsky and Second Scientist Jones. Another 15% suffered brain damage. The Calculator engaged the Pacification Protocol, which expanded its operations into the Buena Vista nuclear reactor complex and industrial facilities in Canyon City and Great Bend to supplement the vault's production capabilities.

The Chicago region was full of rumors of a "Menace from the West," arriving to exterminate all life, and clash with raider tribes, settlements, and super mutants in its march east of the Rockies. The Calculator captured Brotherhood of Steel General, Simon Barnaky, who was transformed into a humanoid robobrain and began his service to the Calculator as its adviser and guardian.

Endings
Although the Calculator had begun rapid expansion and had attempted to eliminate the Midwestern Brotherhood of Steel, Vault 0 was breached by Brotherhood forces led by the Warrior. They would have to defeat the robots and Simon Barnaky before meeting the Calculator.

The eight brains crucial to the Calculator's function are destroyed, so it requires a new brain to continue to operate. The Warrior has three choices, which determine the game's ending:
 * Merge with the Calculator, taking control of it and using its resources for the Brotherhood.
 * Allow Simon Barnaky to merge with the Calculator, which would result in a new Brotherhood of Steel and anti-mutant regime.
 * Do nothing, allowing the Calculator to shut down forever, or destroy it entirely.

Appearances
The Calculator appears in Fallout Tactics and and Fallout: Wasteland Warfare.

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." They also shared that their original concept 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."
 * 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.''"
 * The binary on the Calculators Screen reads 010011001 01001011100 001000100 01100100011, which translates to "L¥Â##."