Icom ID-800H Product Pagehttp://www.icomamerica.com/en/products/amateur/dstar/id800h/default.aspx
Icom ID-800H Instruction Manual (PDF, English)http://www.icomamerica.com/en/downloads/DownloadDocument.aspx?Document=154
Chapter 1 - Panel Description
Page 6 - DATA socket (8-pin mini-DIN on rear panel) Pin Assignment
On the ID-800H, the Icom radio designers doubled up the 6-wire PACKET interface and the 3-wire RS-232 serial interface, due to limited space.
For RS-232 (which your GPS would use): 2, 4, 7
For PACKET (6-pin mini-DIN outline in 8-pin socket): 1, 2, 3, 5, 6, 8
Chapter 11 - Digital Mode Operation
Page 91 - GPS Operation
Cable used: Icom OPC-1384 (8-pin mini-DIN to DE-9)http://www.multitech.net/developer/products/multiconnect-ocg/hardware/multiconnect-ocg-d/rs232-serial-port-pinout/
The terminology, used in the Icom documents, for pin function descriptions are a bit counter-intuitive. RS232 IN means into the attached device and RS232 OUT (GPS) is output from the attached device.
Your GPS must support: NEMA 0183 output at 4800 baud, RS-232.
I understand there is a non standard port on the back, and an over priced cable that converts it to a 9 pin serial port,
I chuckle at some comments .... How good are your soldering skills for this small connector?DIY BUILD HINT: LOOK for surplus 8-wire extension cables (with molded 8-pin connectors) for old Apple Macintosh or Apple LaserWriter printers. It is also used on a game console. OLD computer parts stores at Purdue University have stashed them somewhere.
They are all sold on eBay. I always have a couple 6-pin and 8-pin mini-DIN pigtails in my cable box !
Easier to cut cable in half and wire up a DE-9 connector this way !!
The 8-pin mini-DIN was used as the serial connection (Apple Laserwriter) in the Apple Macintosh (circa 1984) ... and Gwyn Reedy, W1BEL (sk) founder of PacComm, used that same 8-pin mini-DIN connector as a RS-232 serial port (used same Apple pin assignments) in 1989 for the PacComm PSK-1 (400 bps PSK telemetry from Oscar 10 and 13).
IF you desire DIY, then build a breakout box with the 6-pin mini-DIN (Packet/DATA),
which is same PS/2 connector for mice & keyboards AND
the 3-wire RS-232 DE-9 connector or GPS, terminal, etc.
Good Luck with project.