On 2011 Jul 17, at 5:39 AM, David Gesswein wrote: Just took a look at the schematic to see what it might take to fake a keyboard enough to fool it. A little experimentation and it turns out that connecting the data line (ring) to +12V (tip) after it has been powered up (seems to need the transition after power-up) brings up the SET-UP message and flashing cursor after a few seconds. Interesting signalling scheme on the data line, bidirectional signalling is accomplished with some comparators and resistor networks (and some C) on each end, but it seems the keyboard is also clocked signals: clock and data to the keyboard and data back from the keyboard.