Ok, Got both data sheets..... Wow this is exciting Now the Oncore data sheet (linked above) has a "Suggested RS-232 GPS Receiver to Computer and Time Sync Interface" It has the PT5101 on there, so I'm guessing it is similar to what you did. But it uses a MAX233 on there, which I saw mentioned by someone else. Is this basically the same thing you have? I just take out the time circuit, and the 2 wires going in and out, just go together? Thanks for all your help! I love this place!