I have the SEA 235
radio (mine is slightly newer and microprocessor controlled but it should be similar to yours). In my case, I have the P1 connector (which is used for the
remote head), also labeled the SEABUSS connector. You connect a
remote head to this.
The P2 connector is a
serial port looking connection but the pinout is different. You can attach a
serial cable to this that you connect to you computer. Make sure you can the serial cable and only connect pins 2,3,5 which stand for data in, data out and ground. You can use the serial connection to set the frequency automatically. Airmail supports the SEA 235 natively, check to sea if it would
work with the SEA 322, it may or may not.
The P3 connector has many connections. Find the PTT, GND, LLAF and TXAF. You connect the PTT to the
Pactor PTT (this is push to talk), GND to
Pactor ground, LLAF is your received audio, TXAF is your transmit
radio. The Pactor model will drive the radio but will not set the frequency. You need to this on the PC side. I hope it helps. PM if you want to brainstorm.