Patched version of sample code from here: http://learn.adafruit.com/minipov3/download
Tested working on MacOS Mavericks with Keyspan USB-Serial adapter and CrossPack 20131216.
Here are some simple tools for generating custom messages/images. http://tn42.com/minipov http://diyode.com/minipov/ http://www.repulsor.net/minipov/