The circuits described use transistors as bidirectional switches in conjunction with bistable circuits and short delay lines. The bistable circuit is of a type from which registers used in a digital computer may be assembled. By connecting bidirectional switches in various ways between digits of registers, any one of the operations of transfer, exchange, shift and count can be carried out in a time less than 0.2 microsec. The transistors used in the bistable circuit and for bidirectional switches are of the surface-barrier type. The delay cable provides a delay of 60 millimicrosec.