Water chip

A water chip is a device which regulates the filtering and recycling systems of a water purifier and monitors the output for any contamination. It is a standard piece of equipment included in all Vault-Tec vaults.

Background
The events of Fallout begin after Vault 13's only water chip breaks, and the only means to compensate for the diminishing water supplies is to leave and find a new chip. The original Vault Dweller, although not the first to be picked for the task, is sent on a quest to find a replacement in 2161. After encountering many people and places in the wastes of southern California, he finds a suitable replacement chip in Vault 12, the vault underneath the Necropolis, and returns it to Vault 13.

Ironically, due to a mix-up with shipping orders, Vault 8 received the additional water chips that Vault 13 had ordered in place of their second allotted Garden of Eden Creation Kit, which went to Vault 13. On the second level of Vault 8, 420 water chips can be found and taken, though they lack value for monetary bartering.

Water chips were also used as test items by James in experiments to try to find out how to fix the Jefferson Memorial water purifier for Project Purity.

Characteristics
The fact that this item is referred to as a chip is a bit strange. The in-game visuals of the device, both the 3D rendering and the background circuit diagram, indicate that it is built entirely using thermionic valves, not even discrete transistors, in the traditional style of such 50's technology, as a metal box chassis with protruding glass vacuum tubes - the "chip" may not actually contain any silicon at all. The name is also slightly misleading in that the chip itself does not produce or process water, but controls other equipment that does.

Locations

 * Vault 12's Command Center, in a computer.
 * A grand total of 420 chips can be found on the second floor of Vault 8, in crates in certain rooms that can only be opened with a high Lockpick or Strength.
 * One can be found in a locked locker in Vault 13 (Fallout 2 only).

Behind the scenes

 * The blueprint shown in the photo is actually a schematic diagram published by Radio & Television News for a Theremin, a type of musical instrument.
 * Through an ironic twist of fate - primarily due to the Guardian of Forever - the Chosen One in Fallout 2 can be shown as the guilty party in breaking Vault 13's original water chip by traveling back in time to the Fallout era, setting that story in motion.