Interfacing with a (reasonable) modern GPS is piece-of-cake, just hook one RS232 and receive NMEA (simple ascii based protocol (ahum). Last time I checked, I received an date/time line at 0.5 Hz. -----Original Message----- From: pic microcontroller discussion list [mailto:PICLIST@MITVMA.MIT.EDU] On Behalf Of Jinx Sent: woensdag 23 januari 2002 3:31 To: PICLIST@MITVMA.MIT.EDU Subject: Re: [EE]: Replace old chips ? (3) use data from the ship's GPS system. This appeals to me but I know nuffink about interfacing to a GPS unit. Either I can get the data (RS422 ?) and extract the information, or detect the regular packets of data and reduce them to simple timing markers, unless GPS units have a handy 1Hz output somewhere -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics