It mentioned it was a Japanese input, so my guess is that D4 will be their regional hdtv connection. Like DVI will be here[echostar and dish network will be rolling out the new boxes later this year]. The bottom line is you will want to connect your dvi to your tv so if your tv does not have it, thats where your problem lies. Im sure there will still be a coaxial or optical from the cable box to the 950, okay? So buy buy buy