An authorization code can be input into the GPS receiver using any simple terminal program (i.e., HyperTerminal) -- this solution will describe how to use NovAtel's GPSolution software to accomplish the task. Please ensure that you have a valid authorization code from the current firmware that is running on your GPS receiver before continuing. If the firmware, model, expiry date, or serial number changes, then a different authorization code will be required. - connect to the GPS receiver using the GPSolution4 software that was included on the CD-ROM that was shipped with your GPS receiver. If you require a copy of the installation for the GPSolution software, you can download it from here: http://www.novatel.ca/Downloads/fwswupdates.html - use the "Device->Open" menu to create a card configuration for your GPS receiver, or to open an existing configuration. A baud rate of 57600 is a good idea here, although any baud rate will do. For smoother operations, deselect/clear/un-check the box that says "Update Log Definations for Convert4" - when connected to the GPS receiver, open "View->Console Window" - in the text entry box of the console window type: AUTH [authcode] (and then press the Enter key) here's an example: AUTH 563C,2200,B0D7,6230,1EDC,WAASSHPB (then press enter) - when you successfully input the authcode, the GPS receiver will reboot itself. it may seem like GPSolution4 has "frozen" when this happens, because the software is no longer talking to the GPS receiver. To resolve this, select the "Device->Close" menu item, wait about 10 seconds, then reconnect to the GPS receiver (using the "Device->Open" menu item) - in the console window type: LOG VERSION (press enter) ..to confirm that the model of the GPS receiver has been changed correctly. If you see "Invalid Authcode" displayed as the model type, please doublecheck your authcode to ensure that it is valid for this GPS receiver and the current loaded firmware. Authcodes are GPS receiver specific, so please ensure that you match up the PSN with the authcode correctly. You can get the PSN from the LOG VERSION output message, as mentioned above. Note: Be sure to input the authcode exactly as provided, including all commas and uppercase characters.