Hi,
I've been a long time lurker here.
Just thought I'd post a few questions on the above area to see what input anyone can give me here.
I have a JVC KD-SX850 head unit, which has a nifty remote control and wired 2 pin data link output from the head unit to control a 'VCR' connected on the Line-Input to the head unit.

Of course this data link is intended to control a JVC VCR only, but I have reverse engineered the control protocol and managed to decode the 5 buttons available on the remote via the wired control interface [basically +5v, 16 bit long, Sony- S-link like TTL level signals] - with different lower 8 bits for each button pressed on the remote.

The 6 station preset all double as 'VCR' control buttons when Line Input is selected so the same control functions can be done from the head unit or from the wireless remote.

I was wondering if anyone had any technical info on the bus JVC are using for this link [e.g. is it 2 way or 1 way only], if 2 way, what commands can I send the head unit over the link?

Any thoughts would be appreciated