You were in Field Service?

Here's a good one. I have an 11/44, which is supposed to boot RSTS-E from an RA81. Since the SDI cable is inverted at each connector, I am using one cable. I removed the cables attached to the drive, and detached the cables attached to that little box at the bottom of the rack, and attached those to the drive. I have a direct connection between UDA50 and the RA81. I spin up the RA, let it get to READY, and then boot the machine. I tell ODT to B DU0. When the RA has A or B selected, it does absolutely nothing. When both are selected, the drive spins down, and doesn't reset. I have to push RUN/STOP twice to spin it back up. It doesn't give me a FAULT. The RA has passed all the diagnostics, I plugged a terminal. This is very probably my screw-up. What did I do wrong?