The hub sits in the corner of the room next to Computer #1's desk. It took me a couple of days to find it. It networks several of the machines for the Internet, although few can now get online. I don't know what the other devices are for.
I'm no expert, so I have no idea of what these boxes below are for.
The power outlets get a bit scary.
I'm having some trouble sorting out devices because the wires are such a tangle. Many, in the end, are connected to nothing.
There is a switchbox, which I assume was once used for the printer. It is color-coded, and there are corresponding machines. But at the moment, only one computer (#3) talks to the printer with any reliability -- and it isn't one of the color-coded machines.
The most reliable piece of hardware in the whole lab is the trusty HP LaserJet 4. I have heard of no problems with it since my arrival two weeks ago. The HP DeskJet 930C is here, but I won't install it until everything else is worked out.