PURPOSE: To make the length of a required cable as short as possible in the layout of the titled controller by longitudinal array as well as lateral array by changing over switching gates corresponding to the directions of required connections of respective connectors.

CONSTITUTION: Unit selector terminal strings IOCS 1AW4A, and 1BW4B are respectively provided to the connectors A and B, and the terminal strings 1A and 1B for lowest-order bit are connected in common respectively via tristate type gate elements 17 and 18, then connected to the IOCS of a gate array constituting an I/O interface circuit 11. Accordingly, respective I/O units 7 activate the circuit 11 only when either IOCS 1A or 1B obtains a select signal. Also, gate elements 17W21 conducting from the side of connectors A to the side of connectors B and gate elements 18W24 conducting inversely, are collectively and alternately opened/closed by the output of the sliding switch 25 of a housing 8.