Some of you guys might already know - I love Motorola gear. Some time ago I received a 1995 Motorola GP300 from a friend. This old radio was used for the local fire department just before they switched over to digital. I had this one lying around as it was programmed in the 170 MHz range ("2m BOS" here in Germany). I thought I could safe some time for making my own RIB, so I ordered a RIBless box on Ebay which came straight from China for 13 Euro shipped. Not a bad deal. In the end I wasted all the day in troubleshooting and found that some real amateurs are assembling those electronic devices over there in China and also it seems as there is absolutely ZERO quality control. If you are not too good on electronics and troubleshooting electrical devices, better get yourself an original Motorola RIB, there you can be 100% sure that it works (or of course make your own one).
Here is what I found (after several hours):
The solution is easy:
So if your China Interface is not working, open it up (Torx 8) and make sure all connections are ok, well soldered and no rubber insulators prevent the data from flowing.
Another thing, my Interface came without any documentation and papers. There are 2 open leads at the end, red and black. You have to apply voltage to them. 8V stabilized on my bench PSU worked perfect for me.
BTW: I used the old DOS software on my old 3 GHz Windows XP computer, emulating DOS with DOSBox. Here is a good documentation: https://kk6jyt.com/motorola-radius-gm300-programming/
UPDATE 13.06.2017 (GM1200 not possible):
With the modification shown above I was able to program my GP300 but not my GM1200 mobile rig. Although the GP1200 was not explicit noted in the article description I re-engineered the china interface and found out that my RJ-45 jack for the microphone socket was not correct wired for the GM1200 series. Pins 5 and 6 were changed, so I made myself an adapter to fix that issue but it still did not work.
On the serial 9 pin D-Sub connector for the PC there were only 3 pins connected. 2-red, 3-white and 5-black. When I checked the original Motorola service manual I found out that the original RIB has also pins 4 and 9+8 connected (already converted to 9 pin Sub-D) for the busy and busy- lines. So my Ribless interface from China can not work with my GM1200, but works perfect after my small modification on the GP300 series.
Btw: I received my money back from the chinese vendor, when I showed him this blog article. Maybe he can make his interfaces a bit better now. For the GM1200 I built myself an 100% Motorola spec matching RIB with the 'original' parts.
This RIBless Box should work on (not tested, according to the article description):
GP88, GP88s, GP300 und GP350, P110, CP040, CP100, CP140, CP150, CP160, CP180, CP200, CT150, CT250, CT450, CT450-LS, GP3688, GP68, GP88S, GP2000, GP2100, P020, P030, P040, P080, PR400, PRO2150, PRO3150, PRO7550, GTX Mobiles LTS Mobiles MARATRAC Mobiles MAXTRAC Mobiles RADIUS Mobiles Sportbase Mobiles SM10, SM50, SM120, LCS2000, LTS2000, MCX600, MCX1000, MCX760, MCX780, PRO3100, PRO5100, PRO7100, Maxtrac 50, 100, 300, 300+, 820, 840, M860, M1225, GM140, GM160, GM300, GM328, GM338, GM339, GM399, GM340, GM360, GM380, GM398, GM640, GM660, GM950, GM950E, GM950I, GM1280, CDM750, CDM1250, CDM1550, CDM1550LS, CDM1550LS +, CM200, CM300, PM400, GR300, GR400, GR500, GR1225, M10, M100, M120, M130, M200, M206, M208, M214, M216, M400