...I don't feel like searching the BBS

Ignore the wealth of information that already exists and get everyone to re-type it 'cause you're feeling lazy. Nice.

From memory, on the docking sled serial port port connector, the Amp Remote (12V) line is on pin 4, and can handle 3A. TxD and RxD are on pins 2 and 3. They are the opposite of whatever the empeg itself is, but can't remember which way around. If your GPS is TTL level (ie GPS module from somewhere like bgmicro) then you'll need to convert the voltages, but if you bought an off-the-shelf unit then you probably wont need to. Check the specs.

Of course, none of this information is guarranteed to be 100% correct. It is from memory. But it is all available for free on this BBS.

Non-obvious but useful search terms include Oncore, Trimble, SVee6, streetfinder.