Product information: http://www.signav.com.au/SignavDataFrame.html
This receiver is the focus of GPL-GPS since it's based on the GP4020 chipset, has a reasonable Flash/SRAM selection, and has most of the pins routed to a SMT 51-pin connector on the bottom of the receiver.
Testing the serial link to the MG5001 (requires commercial firmware):
Plug in the carrier board and MG5001, and make sure all switches are down towards "RUN". Run minicom (or Hyperterminal). Running at 9600bps, 8N1, send $GPGPQ,GGA,1\r\n which is the same as typing in the terminal $GPGPQ,GGA,1{control-m}{control-j} . You should start getting the $GPGGA message once a second which will confirm that all your serial hardware is working correctly.
[[GP4020 MPC Setup for the MG5001|MpcForMG5001]]