[Radio Wrangler]

That's what I'm expecting. My logic analyser fairly old (though a Philips product.) I haven't started digging into this properly yet. I had a look to see if there was anything obvious, but it looks like a fairly serious job. I've designed I2C interface logic for FPGAs in the past, doing multidrop connection along long cables or short cables and being agile enough to tell what speed to use. If it is I2C I may be able to determine which processor is waiting for the other. The problem is that the keyboard processor s inaccessible when the unit is plugged together enough to power up.

David