An apparatus for use with a first data device, a second data device, and a third data device operable to generate one of directly and indirectly an interrupt signal and to disable one of directly and indirectly the interrupt signal. The apparatus includes a switch connectable to the first data device, the second data device, and the third data device, the switch in a first state connecting the first data device and the second data device, the switch in a second state being operable, upon detection by the switch of the interrupt signal, to disconnect automatically the first data device from the second data device and to connect automatically thereafter the first data device to said the data device.