Abstract: Expanded utilization by several different devices from a single output port such as the RS-232 port of a personal computer is effected by connecting the data line of the serial output port in parallel to several different solid state switches each of which is capable of routing the data information to one or the other of two utilization devices. Selection of a particular switch is effected through micro-controllers which are connected to the control line of the serial output port. Unique address messages are supplied to the host computer at a baud rate which is high compared to the normal rate of change of signals on the control lines and these addressing signals are uniquely decoded by the micro-controllers to select a specific micro-controller, then to select a specific output of that micro-controller activating a solid state switch to select the utilization device to communicate with the computer over the data line.