PURPOSE: To attain bootstrap without using a read only memory by sending the execution control of a processing component for executing processing logic to the inside of an external storage device when the processing component starts resetting at the time of being connected to a system bus.

CONSTITUTION: A random access memory 140 is connected to the processing component 101 so as to store data or an instruction to be handled and executed by the processing component 101. An I/O controller 103 receives an input/output command from the processing component 101 through a bus 104 and generates a requested signal. A memory card interface controller 102 is an interface and a controller to which an attachable/detachable flash memory card 112 is inserted. The flash memory card or a specific storing place at another external storage device is accessed by adding an address to the controller 102 through the bus 104.