Spring cleaning wave

Must be a wave of spring cleaning going on, during a visit to a nice local salvage yard I noticed much movement was going on. Turns out next week a big truck will pay a visit and ALL the old stuff is going. Former items of endless dickering, were now "flexibly" priced so I bought a trunk load of junk. With of course a few bits of treasure. Central Point copy card floppy controller, (2) 4869 external floppy drives, (is a 4865 3.5" drive interesting?), an extender card (about 6x8 inches I guessed it might be S100?) with a ribbon cable to proto board and wire wrapped sockets, 2/3 of a shoebox of 5.25 floppies for a Toshiba T100 CP/M computer, basket case stylewriter 1200, and misc stuff. Big iron just rolling into the yard, 4 of those baby rack chassis, one a MicroVAX II, and the rest each holding 3 or 4 HP 7945 computers all daisychained together with that weird HP skinny centronics looking connector. A monitor, keyboard, and a couple HP mice also present, so I assume its a working system. What the heck is it? I looked one or two of the 7945 boxes over, and didn't learn much. I think they also said they were 9000 series 300, but most only had the weird HP connector on the back (are they just drives or what?). TU81 tape drive also present, but I don't know if related. This new stuff isn't going on the truck next Tuesday, but a lot of other stuff is (mostly 386 and older chassis, broken monitors, odd monitors (bits of an Omron computer, a Next slab, etc.) Everything is in South Orange county CA BTW.