DRA-Pi-Zero Mini-DIN-6 Connector Pinout:

1 = TX Audio - selected by TX Jumper - Left or Right (Default is Right)

2 = Ground

3 = PTT

4 = 9600 Baud RX Audio - Selected by RX Jumper in the "9600" position

5 = 1200 Baud RX Audio - Selected by RX Jumper in the "1200" position

6 = N/C