Hi,

   There are five connectors and two switches that look "stock": (1) a
   DB25M, labeled with arrows pointing left and right; (2) a DB15M,
   labeled with a silhouette of a keyboard, something that is probably
   supposed to be a monitor screen, and an arrow with the head circled;
   (3) a DB9M, labeled with what is clearly supposed to be a printer; (4)
   a BNC connector labeled with a strange little crosshatch and the letter
   A; (5) a DB15F labeled with a similar crosshatch and the letter B; (6)
   a two-position switch labeled A and B, near connector 5; (7) what
   appears to be a momentary-contact pushbutton labeled with a triangle
   inscribed in a circle.

Here goes:
1 - serial port (with some modem signals)
2 - keyboard, mouse and video connector
3 - another serial port, sans modem signals
4 - thin ethernet
5 - thick ethernet
6 - switch selects between 4 and 5
7 - reset button

  There are also three spaces at the bottom back, labeled A, B, and C.  A
  has a 50-pin Centronics connector, B has a DB50F, and C has a blank
  plate behind it.  I was unable to disassemble the machine very far, but
  I did determine that the DB50F at position B has a small board behind
  it marked "ST506/512 INTERFACE ADAPTER", with two ribbon-cable
  connectors with nothing plugged into them.  The Centronics connector at
  A is attached to a ribbon cable that disappears into the machine.

Can't remember which is which (it sounds like you can tell), but the one
is for a second ST506 (RDxx) drive in an expansion box and the other is
a SCSI port that DEC only used for the tape (TK50Z).

(the above questions are answered above, except that DEC didn't like the
 slide lock (I agree:-), so they used screws instead.)
- Can I use the monitor/keyboard from a MicroVAX-II/GPX I have (IIRC,
   NetBSD does not support the GPX display)?  The connectors look
   physically compatible, for what that's worth.

I think so. Some really old VAXstation IIs had a different mouse with a
DB9 or 15, but so long as the mouse has the round connector, I think it's
the same.

- How do I get the thing apart?  I managed to take off the base, but
   further disassembly seems to require snapping off either the front
   or back plastic piece, neither of which wants to come off.  Or do I
   just have to be firm and force the sides to spring apart enough to
   lift the metal cover off the top?

Take out the 4? phillips head screws on the bottom and then slide the
box off the front. It can then be dissected by taking out screws in various
places. (Not the easiest DEC box to work with, and takes some finagglin
to get the cover off, as I recall.)

Can't help with the install, but here is a list of connector pinouts
you might find handy. (Also, if you don't have the DEC keyboard/mouse/video
cable and want one, send me some email, as I think I have a spare one
lying around I can give you.)

Good luck with it, rick
--- connector pinouts ---
VAXstation 2000 System Jumper
(on KA410 motherboard about an inch or so directly behind the thin ethernet
  BNC connector)
VAXstation 2000 - jumper on pins closer to thin ethernet BNC
MicroVAX 2000   - jumper on pins farther away from the thin etherner BNC

VAXstation 2000 Connector Pinouts

Printer port (J3)
1 - ground	2 - xmit_data	3 - rcv_data
4 - no conn	5 - +12VDC	6 - no conn
7 - ground	8 - ground	9 - fer_ena (jumper to pin 8 for console)

Video Connector (J5)
1 - vid_red	2 - color_ret	3 - mono_ret
4 - +5VDC	5 - mouse_rcv	6 - kbd_grnd
7 - ground	8 - +12VDC	9 - vid_mono
10 - vid_green	11 - vid_blue	12 - -12VDC
13 - mouse_xmit	14 - kbd_rcv	15 - kbd_xmit

Comm Connector (J10) - RS232 with partial modem control
Tape Port Connector (J13) - single ended SCSI

RD/RX Cable Pinout (J7)
1,3,5,7,9,11,13,15,17,19,21,23,25,27,31,34,37,40,43,46,48,51,54,57,60 - ground
2 - lospeed
4 - rxindex
6 - rxsel0
10 - moron
12 - rxdir
14 - rxstep
16 - rxwd
18 - rxwrgt
20 - rxtk00
22 - wrtprot
24 - rxrdata
26 - rxhsel0
28 - rxrdy
29 - rdhsel3
30 - rdhsel2
32 - rdwrgt
33 - skcompl
35 - rdtk00
36 - wrtfault
38 - rdhsel0
39 - rdhsel1
41 - rdindex
42 - rdrdy
44 - rdstep
45 - rdsel0
47 - rdsel1
49 - rddir
50 - dselack
55 - rd0_wdath
56 - rd0_wdatl
58 - rd0_rdath
59 - rd0_rdatl
8,52,53 - no conn

Expansion Disk Data Cable (J9)
2,4,6,8,11,12,15,16,19 - ground
3,5,9,10,20 - no conn
1 - dselack
7 - +5Vdc
13 - rd1_wdath
14 - rd1_wdatl
17 - rd1_rdath
18 - rd1_rdatl