Backward compatible extended USB plug and receptacle with dual personality

A multi-personality serial-bus interface comprising:

• dual-personality socket compatible with a standard-protocol plug and an extended-protocol plug, the dual-personality socket including a socket substrate to define a socket cavity to accept one of a standard-protocol plug and an extended-protocol plug, the dual-personality socket further including standard metal contacts that make contact with the standard-protocol plug and extended metal contacts that make contact with the extended-protocol plug but do not make contact with the standard-protocol plug;
• a standard-protocol processor, coupled to the standard metal contacts, for generating and receiving signals using a standard protocol for transmission through the dual-personality socket;
• an extended-protocol processor, coupled to the extended metal contacts, for generating and receiving signals using an extended protocol for transmission through the dual-personality socket;
• a multi-personality bus switch to connect the extended metal contacts to the extended-protocol processor means when operating in a first extended mode, and to disconnect the extended metal contacts when operating in a standard mode;
• and
• program for executing an initialization program that initially sends and receives commands using the standard protocol through the standard-protocol processor, but switches from the standard mode to the first extended mode to send and receive commands using the extended protocol through the extended-protocol processor when the extended-protocol plug is detected,
• wherein communication through the dual-personality socket to the extended-protocol plug initially uses the standard metal contacts, but switches to using the extended metal contacts.