Mainframe core

The mainframe core is a junk item in Fallout 76.

Characteristics
Completion of the Mission: Countdown quest requires a total of 15 undamaged mainframe cores. These can be obtained in one of two ways: by collecting damaged mainframe cores from the computer consoles in the lower level of Site Alpha, Site Bravo, and Site Charlie, and then repairing them at a tinker's workbench. Alternatively, a small number of undamaged cores can be found scattered in the boxes and shelves that are present within the silos.

In the add-on Nuclear Winter, mainframe cores can be found in Vault 94 during vault raids, and are used to replace damaged ones in Vault Mission: Dead in the Water.

Crafting
A damaged mainframe core can be repaired for use in the Mission: Countdown quest:

Locations

 * Scattered randomly in the lower level of Site Alpha, Site Bravo, and Site Charlie.
 * In Vault 94 during Vault Mission: Dead in the Water.