Abstract: There is disclosed a circuit arrangement comprising a microcomputer, wherein certain terminals of the microcomputer may be used as either input terminals or as output terminals under selective switching control so that a reasonably priced microcomputer with few terminals can be used to control complex functions such as those of a vehicle seat adjusting mechanism. The circuit arrangement also includes a program check arrangement wherein check pulses are superimposed with control signals at an output terminal. The check pulses are used by a multivibrator which resets the microcomputer when the check pulses are not periodic. The check pulses are short in duration and do not adversely affect the operation of a relay coupled to the output terminal.