[cctalk] Re: PDP-11 thingy. What is it?

Hi all, I picked up this PDP-11 thing. Can anyone help me understand what it is? Pictures are here: https://w2hx.com/?prefix=x/What-Is-It/PDP-11-Thing/ I could not find any designation on the backplane. It is a wire-wrappable backplane. I don't know if it is Qbus, unibus or whether it is 18 or 22 bit addressing (this is because I am a newbie in this area).