null modem cable - Computer Definition
An earlier RS-232 cable used to connect two computers in close proximity for file transfer. In style before the USB interface came out, a null modem cable attached to the serial ports of both machines. By crossing the sending wire with the receiving wire, it simulated analog modems and the public phone network. A counterpart cable was also available that used the parallel port for higher transfer speed. See Laplink cable. See also crossover cable.