A program supplied from a personal computer via an interface 31 is processed according to a program stored in a ROM 36, developed in a RAM 33, and executed by a CPU 32. Data resulted from the program execution is stored into a nonvolatile memory 34. The interface 31, CPU 32, RAM 33, nonvolatile memory 34 and ROM 36 are housed in an adaptor 26 formed integrally as a semiconductor IC.