Water chip

The Water Chip is a device which controls the water recycling and purification process in all Vaults. The original Fallout game began when Vault 13's water chip apparently broke and there were no replacements. The original Vault Dweller is sent to find a new one, and finds one in Vault 12, the vault underneath Necropolis and returns it to Vault 13. Due to a mix up in shipping, Vault 8 attained Vault 13's additional Water chips, in exchange for their additional Garden of Eden Creation Kit.

The use of the name "chip" is remarkable given that, in the Fallout universe, integrated circuits (the origin of the word, as in "silicon chip") seem to have never been invented, all technology relying on masses of discrete components and hence being huge and cumbersome. Indeed, 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 tubes - the "chip" may not actually contain any silicon at all.

Through another strange twist in fate, primarily due to the Guardian of Forever, the Chosen One in Fallout 2 actually broke the original Vault 13 water chip by traveling back in time to the Fallout era, setting that story in motion. (Whether or not this is canon is debatable.)

Apparently, many vaults are in short supply of water chips, or run low on them over time. In Fallout 3, the Lone Wanderer can opt to force the residents of Vault 101 to leave their sealed vault by destroying what is apparently their only remaining water chip. (but this might just be a reference to the people who played fallout 1)

hydroprocesor Водный чип