If you only need one input, I used a 422 to RS 232 converter from US converters, combined with a Keyspan Serial to USB converter. It works well at both 38400 (AIS) or 4800 other NMEA output. http://www.usconverters.com/index.php?main_page=product_info&cPath=65&product s_id=180 http://tinyurl.com/krhl54 Dave Legrow