An insertion and identification scheme between the main unit of a Personal Digital Assistant (PDA) or handheld device and an option pack. Upon insertion, the hardware interface invokes a device manager on the main unit that interrogates the option pack on its features without significantly impacting battery life. The interrogation includes data on drivers, applications, configuration and miscellaneous requirements of the option pack. This identification process allows the option pack to store information, drivers and applications on the option pack, so the main unit does not have to use its memory to store information on a large number of option packs. Further, the insertion scheme provides a means of checking the power availability in the main unit before allowing the option pack to fully power-on.