rodbailey

This information copied from the manual page 10, Version 2.0
Looking at the connector you will find 3 plastic location notches.
Using the same numbering scheme as the manual, pin 3 is directly between the
2 small notches. The other 4 pins are numbered clockwise.
Alternatively, if the GPS is held upright with the connector at the top, Pin
1 is at 6 o'clock 2 at 8, 3 at 10, 4 at 1 and 5 at 4.
Pin 1 is external antenna power supply output @ 2.7V. I wouldn't take more
than 50-100mA from here.
Pin 2 is DC input 10-20V
Pin 3 is NMEA / MLR data output
Pin 4 is NMEA / MLR data input
Pin 5 is Gnd (0V)

To wire your MLR to a PC DB9 serial port connect
MLR pin 3 to PC pin 2
MLR pin 4 to PC pin 3
MLR pin 5 to PC pin 5

The MLR connector is very similar to a mini-DIN socket, although the pin
layout is a bit different. Careful use of hot melt glue, might allow you to
reuse an old PC PS-2 mouse / keyboard connector.

Alternative method of making a plug
1) Put a thin layer of grease onto the MLR connector
2) Put a straight bit of wire (eg paperclips) with a wire soldered to it
into each pin hole.
3) Drip hotmelt glue over the connector. The grease should stop it sticking
to the MLR.
4) Ensure the glue fulls up the ring around the connector
5) When the glue has hardened, remove the "connector" you have just made

This should work with proper glue too.

The connector won't be very sturdy, but mine has lasted ages for downloading
flights to my PC. I wouldn't use it for connecting to a PDA in flight unless
you can make a good secure connector though.

Hope it works for you!
Although it worked for me, don't come crying if you blow up your MLR / PC or
glue yourself to the MLR!