Connecting a BC80M cable to a RLV12 controller

I finally got a drive select plug for my RL01 drive and would like to try connecting it to my 11/73 but I find that the cable that is supposed to plug into the RLV12 controller isn't keyed so it can go in either way. How do I tell what the correct orientation is for this cable? I'm assuming that if I plug it in backwards I'll fry the controller and/or drive. The only markings on the end of the cable that connects to the controller are the manufacturers name "Berg" and the letters A and B near one end and VV and UU near the other end. How should this cable be inserted into the RLV12? Also, assuming I get this straightened out, what should expect to happen on power up? Should the 11/73 automatically boot from the RL01? I have an MXV11A boot board installed. Or do I get a console prompt and have to select the boot device on the console? Thanks, David