Kenwood TS-50/AT-50 communication protocol

[WA4UNS]

I've been scouring the web... I'm looking for the communication (command) protocol between the Kenwood TS-50 and the AT-50 tuner. I already know the data setup (4800 baud, etc) and timing of the TS and TT lines. I'm looking for the command/response exchange between the units. I'm needing this info to design and build an interface between the TS-50 and the Tarheel M300 screwdriver I'm using in my mobile. Being able to use the "AT Tune" button on the TS-50 would be a great help when I'm changing bands while flying down the road.

Thanks

Doug WA4UNS