Abstract: The present invention is a system and method that facilitates extendible identification of various peripheral devices coupled to a hand held computer. In one embodiment of a present invention peripheral device identification system and method, an initial pulse of an interrupt signal received by the hand held computer initiates an interrupt routine that continues to monitor the interrupt signal for additional pulses within a predetermined time. A hand held computer peripheral device identification system and method of the present invention correlates the number of received pulses with the type of peripheral device coupled to the serial port. In one exemplary implementation of the present invention, a hand held computer peripheral device identification detection system and method utilizes a hash table to map the number of pulses to a type of peripheral device.