Data-storing device

The present invention concerns a data-storing device, which is coupled to a personal computer through an interface and can enlarge a number of and a kind of devices connectable to the personal computer. The data-storing device includes an interfacing circuit that includes a data communication path through which the data can be bilaterally communicated between the device and an external device, which is coupled to the device with an interface cable, and a power-supplying path through which a power current can be bilaterally supplied between the device and the external device, wherein the interface cable also includes the data communication path and the power-supplying path; a data-storing unit to store the data sent from the interfacing circuit; and a plurality of interface connecting ports serving as input/output terminals of the interfacing circuit, wherein the interface cable can be connected to one of the interface connecting ports.