SACD and DVD-Audio both started out analog only, but there were several digital options that eventually were added to both specs. There was IEEE-1394 (FireWire / iLink), which supported DVD-A first and SACD later, but hardly any hardware ever supported it. There were some proprietary solutions like DenonLink, which again supported DVD-A first and SACD later. HDMI v1.1 worked with DVD-A directly, and eventually some players (the OPPO 970HD was one of the first) would convert SACD from DSD to PCM and use v1.1 to carry it. HDMI v1.2 added support for DSD bitstreams.