Electronic apparatus, such as a personal computer, is described comprising main operative functionality and a power provisioning system for powering the apparatus from an external power source, the power provisioning system comprising:—a main power supply output for energizing the main operative functionality of the apparatus when said power provisioning system is connected to said external power source, and a standby power source for energizing a subset of the components of the apparatus when said main power supply output is not energized, the apparatus further comprising a self contained subsystem including a memory for storing at least one parameter reflecting an internal state of the apparatus, said self contained subsystem being powered by said standby power source and including an encoder for encoding the parameters in an output signal and a transducer for generating a wireless transmission from the output signal, which transmission can be detected in the vicinity of the apparatus, so as to enable the parameter to be received and decoded.