Some notes on ardopc (my C version of ARDOP_WIN)

ardopc is a command line program. If run without any parameters it listens on port 8515, on Linux it uses the virtual sound device ARDOP, and on Windows the first available capture and playback device. 

ARDOP uses a sampling rate of 12000 samples/second, and not all that many sound cards support this directly. So you may have to enable sample rate conversion. This is achieved by adding the following to the alsa configuration. I suggest you add it to the user configuration file .asoundrc, creating the file if it doesn't already exist. Note there is a dot on the front of the name, which isn't obvious with most fonts. 

pcm.ARDOP {
        type rate
        slave {
        pcm "hw:1,0"
        rate 48000
        }
}
This creates a virtual rate conversion device called ARDOP, using the real device hw:1,0, and running the real device at 48000. If the sound card you are using isn't hw:1,0, then change the line to match your device. 

You can specify command line parameters port capture device playback device. On Linux the device is in hw:1,0 format. In Windows it is a number starting from zero. When you start the program it will list all the sound devices so you can select the right one. If you are specifying sound devices you must also include the port, eg

./ardopc 8515 hw:1,0 hw:1,0    (Linux)
or
ardopc 8515 1 1           (Windows)

Apart from the command line params above there is no configuration. All parameters are set from the bpq32 config file, though there are reasonable defaults for most of them.

The program writes debug and session onformation to log files.

As there isn't a GUI, setting the sound card levels can be tricky. The program displays the peak input level every 10 seconds. The program works with signed 16 bit samples, so the values will be in the range -32768 to 32767. Clipping will cause distortion, so it is import to keep away form the limits. I've found in practice that it will work down to quite low levels, but try to keep in the range +-20000.
 

The software can be downloaded from 

http://www.cantab.net/users/john.wiseman/Downloads/Beta/ardopc
http://www.cantab.net/users/john.wiseman/Downloads/Beta/piardopc
http://www.cantab.net/users/john.wiseman/Downloads/Beta/ARDOPC.exe

There is also a Windows version that uses a serial interface instead of the TCP interface used in the other versions. This allows RMS Express (or Airmail) to use ARDOP. 

http://www.cantab.net/users/john.wiseman/Downloads/Beta/ARDOP_PTC.exe

It uses a BPQ Virtual COM port to link to RMS Express. The first param to ARDOP_PTC is the com port number instead of TCP port number.

http://www.cantab.net/users/john.wiseman/Documents/G8BPQ%20User%20Mode%20Virtual%20Serial%20Port%20Driver.htm

Define to RMS Express as a DR7400. Then Pactor Levels 1-4 map to ARDOP Bandwidths 200/500/1000/2000

73, John