Just what's inside a Sony DHG-HDDxx0? - Page 4

HDMI is DRM encumbered. Therefore, keys are exchanged. Wiping-out the firmware and starting over from scratch with a jail-broken unit with our own custom MythDHG build would break the end-to-end encrypted stream as designed in by the creators. Would it become DVI and talk to anything? No idea.

To me, the idea is to wipe it clean of all the proprietary code and go full FOSS, if possible.

If all you want is a shell, I don't think you'll get one, but give it a try. pins 407 and 406 on the Xilleon 226 chip are the ones to try first. My mother-in-law has a stereo microscope that would be good for examining the underside of the main board beneath the CPU to gather clues if the pins are brought out. I wouldn't see myself getting it for a couple weeks.
Edited by davygrvy - 11/16/12 at 7:51pm

An interesting start on understanding how DRM has us by the balls with regards to viewing and recording TV shows off cable (encrypted QAM with a CableCard)

Also http://en.wikipedia.org/wiki/HDCP why DVI can talk to an HDMI monitor, but not the other way.

EDIT: I just got on IRC (#mythtv-users on Freenode) and got the skinny about the Ceton InfiniTV 4 tuner with a CableCard and found that if the channel is anything other than "Copy Freely" (0x00), we can't see it at all under Linux. You'll find CCI restrictions most notably on the very premium channels HBO, Showtime, Cinemax, etc unless your provider is the draconian COX which restricts everything even their OTA simulcasting.
Edited by davygrvy - 11/18/12 at 7:21pm

Well the chance of having a "MythDHG" is less than hell freezing over.
So many things would cease to function that the effort involved would eclipse the benefit.

Cablecard would not work, so at best you would get is in the clear QAM/ATSC channels, which you can do for far less by other devices/methods easily.

Unless of course some FOSS developer has implemented a cablecard interface/API and knows how to authenticate and pair the card to the device.
That would be really cool, since if the hardware was functional, with a FOSS implementation, the premium content could be stored decrypted and in the clear on the HDD.
Additional possibilities include-adding the LAN connector and adding Tivo'esque transfer capabilities, or even better, setting up a NFS share and exposing the clear ts's stored on the device for other household devices to stream......

Maybe the XBMC developers have been working on this in the background waiting for the Rovi guys to exit the business and a XBMC-DHG build will pop up in the next week. :P

Just a pipe dream though....

Careful, you might start a rumor

Time Warner is like that, but they leave the locals (limited basic) to CCI 0x00. Everything else is copy flagged.

Has anyone hooked up a USB keyboard to the Sony and done some methodical experimentation? I originally discovered the front panel service menu by methodically holding buttons down at power up, but it never occurred to me until now to try hooking up a keyboard. If I had been an engineer developing software for this box, I would have found a keyboard very helpful for doing backdoorish sorts of things, especially considering the device already has a display. It's probably worth playing around with.

My Digital TVGOS is gone, but Analog TVGOS is still alive over cable. With that said, I won't be tearing into my unit until that goes as well and I loose the ability to set the time.

The first things to try are Serial to USB adapter and possibly an Ethernet to USB adapter and attempt to to establish a communications link directly with the Linux operating system (Telnet, FTP, or shell login). It's a simple matter to set the time via linux commands.

I didn't know about this thread until today when I saw it referenced in the DHG-HDDxx0 thread.

I had been thinking about writing replacement firmware from scratch but some of the things I read here make me think that this may not be feasible.

However, I had another thought while I was reading the thread and thought I would run it up the flagpole so you guys can shoot holes in it.

I believe the ATSC signal has time information encoded into it and each station encodes some amount of EPG information in the signal as well (the amount varies by station and no station's data is as robust as the TVGOS data). Rovi had equipment at the broadcast stations to inject the TVGOS data stream into the ATSC signal. The recorders still have the capability to update the time and program grid if provided with properly formated data. How difficult would it be to find out where Rovi embedded its data into the ATSC signal and copy the broadcast station's data to the location used by the TVGOS software?

Alternately, what about pulling guide data and time from the Internet via a computer program, recording the information on a videocassette, and playing the tape back into the antenna connection (I don't know if any of the available recording software will allow recording into the undisplayed video lines)?

The idea here is to force the recorder to use the software it already has by manipulating the incoming signal. I don't know if this is feasible, but I haven't seen this suggested anywhere else and thought it might be worth discussing.

I plan on implementing a Addonics ADU2N1G NAU adapter to try to talk to the DHG. A word of caution, since the DHG's USB port is Type A, pin 1 (power) should not be allowed to pass through, a potential conflict. I think the best way is to modify an USB Type A male to Type B female adapter and remove pin 1 from the B female connector. Then use a standard USB Type A male to Type B male cable as an interface.

If you can decode the parameters needed, TVGOS already has the ability to accept data. I'm sure you know how to reach the 753... screens. Instead of 753..., enter 444555555. You then get a prompt. Now, I have no idea how to enter the data, terminate the data, and how to save it. But it's there, like the active serial port data.