A system for transferring power and/or data between a host and a store over a single-wire umbilical cable is herein described. The system comprises a host-store interface configured to allow the transfer of both power and data between the host and a store in operative communication therewith. The store comprises a microcontroller and memory operatively coupled thereto, allowing the microcontroller to be powered on and to receive and store data sent by the host in its memory through a single-wire without requiring additional electronic systems that the store may comprise to also be powered on. This data may later be incorporated into pre-programmed systems onboard the store at full power-on, thereby enabling the reprogramming of the store without powering it on prior to launch.