The main role of the central computer is provide the location of Vault 15, a stepping stone to finding Vault 13.[2]
Optimize the power plant: The computer can also verify Gordon's intel on Vault City's uranium reactor and allow to optimize the Gecko power plant, so that it will provide surplus power for resale to Vault City.[3]
References
↑Vault City central computer: "{222}{}{Northern California Geographical Archive is being copied into Pip Boy database. }" "{223}{}{Copying archive... Broken Hills... Gecko... New California Republic... New Reno... Redding... Vault City... Download complete.}" (VICENCOM.MSG)
↑Vault City central computer: "{238}{}{According to the archives, there is no GECK currently in stock at Vault City's Amenities Office. The people of Vault City seem to have used the only one they had to help establish the place when they came to the surface.}" "{239}{}{Scroll through the remaining information.}" "{240}{}{From what you can make out in the archives, two GECKs were part of every Vault's standard inventory package. Only one was shipped to Vault 8, however.}" "{241}{}{Cross-reference the GECK shipment information.}" "{244}{}{Due to a shipping error, it appears Vault 8 received a box of surplus water chips intended for another Vault. The other Vault most likely received Vault 8's second GECK.}" (VICENCOM.MSG)
↑Vault City central computer: "{173}{}{Insert Gecko power plant disk into the computer.}" "{231}{}{According to the output reports, it looks like Gordon was correct. Vault City's generator is already approaching its limit. Without a new power supply, Vault City will be unable to expand.}" "{258}{}{Reading Disk... Reactor Data: Atomic Power Plant... Efficiency: 43%/75%... Error: Plant Calibration - MD4/gh1... Do you wish to optimize?}" "{263}{}{Begin optimization procedure. }" "{266}{}{Beginning optimization procedure... Optimizing... Optimization complete. Please remove disk.}" (VICENCOM.MSG)