PURPOSE: To decide automatically wrong insertion in a packaging mode by storing both program identification name and the packaging position to each P- ROM and supplying said identification name and packaging position by the P- ROM itself.

CONSTITUTION: A CPU1 is equal to a 1-chip microcomputer, and the CPU1, P- ROM3W5, an input/output control circuit 6 and a constant setting circuit 7 are connected to a common bus 2. The circuit 6 controls the input and output of this system, and P-ROM3W5 record the programs and data needed for the execution of this program. The circuit 7 consists of a hardware switch and sets the program identification name which is executed through this substrate as well as the packaging positiols of P-ROM3W5 respectively.