Yes, it is possible to get sound output from a serial port. Sure, it sounds terrible, but what did you expect. [markrages] ttyplay program first resamples the WAV file to the baud rate of the serial port. It then uses Sigma-Delta modulation to encode the analog signal into a binary bitstream. You should really try this out. The picture above is from when I was testing it out since it only took a minute to grab the parts and a second to compile. Mark says audio quality could be improved by using a higher baudrate. There is a lot of noise though. Somebody want to put together a simple RC filter/amplifier; I can actually think of a project this might be useful for. Read more about ttyplay here.