Shielded twisted pair (STP) FDDI. Early, proprietary schemes for running 100 Mb/s FDDI over twisted pair wiring. SDDI was replaced by the FDDI TP-PMD standard. See also TP-PMD.
Serial digital data interface. A way of compressing digital video for use on SDI-based equipment proposed by Sony. Now incorporated into Serial digital transport interface. See: Serial digital transport interface.