I have a gazillion boxes of various sorts connected to the two TVs in our household, but the longest-serving one is my TiVo DVR. I got it when I moved into my present home and signed up for Comcast ...

Just got off the phone with Comcast adding a new TV package w/HD. Asked the guy about HDMI and was informed that Comast's non-DVR boxes, have HDMI but it "it will not work", only DVR boxes will work ...