Thanks, Bill. Page 165 of the manual also says this:
"You cannot capture audio/video signals coming from the device connected to the HDMI INPUT port or the VIDEO INPUT
jacks and save them into a file on your computer. It is logically impossible because the audio/video input source must be
either the HDMI input or the video input to receive such signals and, to access Windows for any file operations, you must
change the input source to the computer input."
The statement doesn't make much sense. However, when I pointed this out to the tech support rep, he said the manual was wrong! I do have to ask whether you have any personal experience with this Sony or the previous similar versions, because that's the only way I can be sure.
I believe that the RF input must communicate with the PC, because the literature is quite clear that you can use the DVR functions to record TV. If it can't be done via the HDMI or video inputs, then that just leaves RF. That's how the tuners get their signal, and I believe you can record from the internal tuners. The tuners, by the way, are NTSC and ATSC; the specs say nothing about ClearQAM.
I could get a DVR from Comcast, of course, but I would prefer to record to the PC. I'm looking at a short list of other options for getting high quality (if not strictly HD) content into the computer:
Hauppauge HD PVR
Black Magic Intensity Shuttle
Geffen HD PVR
Monsoon Hava Platinum
AverTV USB HD DVR
Any thoughts on these or others would also be appreciated.