Some time ago I got a MTP700 and wanted to program it, but the cost of the programming cable was a little bit too high, and even worse, the cable was hard to obtain for an individual (because of some weird Motorola's commercial practices in my country
). So we decided with a few friends to investigate and make our own RIB for that radio. The result is a simple, yet fully working programming interface than will be sufficient for most Motorola geeks 
I even managed to flash firmware in my MTP700 with that construction!
I opened this topic to share the informations I have. I hope you'll find it useful! This RIB was tested on MTP700, but should work as well with other TETRA radios from Motorola, requiring FLN9636 (portable) or GMKN4067 (mobile) cables.
Here's the schematics of the RIB:
http://img232.imageshack.us/img232/8864 ... bladc4.gif
And here's the bottom connector of the MTP700 (Pin 1 on the left, Pin
14 on the right):
http://img442.imageshack.us/img442/397/pa160054tw5.jpg
There are only 3 lines used for programming these radios: GND, RXD and TXD.
GND goes to Pin 1 on the radio
DATA IN goes to Pin 2 on the radio
DATA OUT goes to Pin 3 on the radio
Then you have to apply 5 - 12V to the RIB (between the "VI" pin of
the 78L05 and the ground). I have done all my programming with about 7.2V and it worked fine.
Don't forget to put the radio in programming mode (keys 1 and 9 both pressed during power-up)!
The radio can be also put in programming mode by applying +12V on the "FLASH" pin of the connector.
Have fun!
