The TDIF (Tascam Digital Interface) is a proprietary format that uses a 25-pin D-sub cable to transmit and/or receive up to eight channels of digital audio between compatible devices. Unlike the lightpipe connection, TDIF uses a bidirectional connection, meaning that only one cable is required to connect the eight ins and outs of one device or another. Although systems that support TDIF-1 cannot send or receive sync information (a separate wordclock connection is required for that), the newer TDIF-2 protocol is capable of receiving and transmitting sync through the existing connection, without additional cabling.