This is the code to accompany two blog-posts I wrote about transfering data between computers using a jury rigged sound-card modem.

Note that these programs are mainly educational, and if you want to do this in a critical situation, you'll at the very least want to add Hamming-code or some other error correction scheme.

The source code consists of a multitude of programs.

• playback and record plays and record a data stream using OSS. If you don't have OSS support, ALSA can emulate it with the 'aoss' wrapper.
• generate turns a binary file into raw wave data.
• generate_psk does the same, except encoding it with phase shift keying.
• analyze turns a recording into data again
• analyze_psk does it for PSK-encoded data.

The original articles can be found here: file transfer over sound card file transfer over sound card ii phase

However, due to changes tot he blogspot platform, the formatting doesn't work very well. I've joined the two into one well-formatted article:

file transfer over soundcard directors

The code is public domain.