anyone have info about hacking the protocol? i'd like to know.

More specifically the baud rate the data is sent at... long shot i know, but i dont have an oscilloscope.

looking at interfacing to a computer, utilising the buttons of the h/u to navigate folders and songs...

made a little circuit to convert rs232 to the IPBUS's can-like system.

Cheers,
Bill

Mate im not sure its all that complicated, the actualy sound signal component of the IP bus is just a normal line level left, right and common. There is information around on the net on how to wire up your own aux input for the IP bus connector and these might have what some of the other pins are. The only device i know of that does what you need to figure out is a wired remote. These are available from pioneer as a marine remote (ive not seen these in aus). If you could get your ahnds on one of them you coudl figure out the signals it uses.