I got the qbone into the MicroPDP11/23+. The CPU is in slot 1, Memory board is in slot 2, and the Floppy/Hard Drive controller was in slot 3. The motherboard is a 9278 so these slots are all Qbus-C/D. From slot 4 they are Qbus-Qbus. That's significant because the CD Grant Continuity jumpers have to be opened if the Qbone is placed in slots 1-3, otherwise they are left closed (as shipped - the way I installed the board).
I elected to remove the drive controller and place a 9047 Grant Continuity card in slot 3 for physical clearance and the Qbone in slot 4. There was some discussion here of configuration changes required for the computer to have both a Qbone emulated drive and the RQDX board installed at the same time - it seemed simpler to remove the RQDX but if I want to format a hard drive or make floppies I'll have to resolve that problem.
Again, what fun! I followed the Unibone instructions on Retrocmp to determine the current memory size and then emulate the rest possible with 22 bits - worked great - the computer thought it had 4 megs as far as I could tell.
I then (tried) following the Unibone instructions on emulating an RL02 and booting RT11. That was less than successful - either there are differences in the Qbone v. Unibone software or more likely, my screen on the Ubuntu computer is too small and swapping from Firefox to terminal windows involved too much window shifting given the learning curve I was enjoying*. I did see the drive on the MicroPDP boot screen finally, a small victory.
Throwing caution to the wind, I ran some of the scripts in the base directory of the Beaglebone - I successfully booted RT11v3 and then re-started the PDP/Qbone and booted RT11v5.5, both with minimum end-of-script finagling.
An afternoon of fun and enough success to experiment further.
* There are two consoles running - the Beaglebone/Qbone via ssh over the network to run the configuration scripts and the PDP11 console via serial port on the CPU card. Running the card outside the computer at first was valuable experience for the real thing.
Some of my explanation is possibly a bit elementary for the group but hopefully helpful to anyone starting out. The group's assistance and encouragement have been amazing. And thanks to Joerg Hoppe for making this possible at all.