Dear Antonio,
   
   Thanks for the clarification! But I still have a few questions. You
wrote:
> I no longer have my original post so I don't know whether I said or not,
> but the MicroVAX 2000 and the VAXstation 2000 are the same board.
   Whew! This means that one can convert not only from VS2000 to MV2000,
but also vice-versa! Plus the conversion is complete and not approximate as
with KA41/42!
> add or remove the external converter unit that
> gives you MMJs instead of a video output.
   Or, if you don't have the converter but have a BCC08 cable, you can
connect its 9-pin end to the DB9 connector on KA410 and its 25-pin end to
the terminal. But this method has the disadvantage of not giving you ports
0 and 1. And of course you can make your own cables, and in this case you
can do anything. The good thing is that the pinouts are documented in the
owner's manual. (Documentation for the commoners! What a concept!)
> I believe the console scribbles KA410-A or KA410-B depending on the
> position of the jumper [...]
   Wait a minute! These -A and -B things are related to DEC OS licensing
(single-user vs. multiuser or something like that), right? So one can
actually change the licensing status with a simple jumper? Cool. I have
thought that DEC would make a special 200-pin surface-mounted ASIC just for
this purpose, unmarked like a military helicopter, to make sure that people
don't even dare to touch this thing. Hey, I'm impressed! Can you also do
that with MicroVAX vs. VAXserver distinctions on KA650/655 and KA41?
   But what about "F..." vs. "F_..."? Does the system ROM lie that the mono
video doesn't exist when it's not used for the console? Is this based on
the licensing jumper setting or on the console selection? Or maybe DEC did
put in different EPROMs in MV2000 and VS2000 after all? And I'm still
curious whether there is some actual circuitry that's just for the mono
video and thus could have been removed on MV2000, or is mono video a purely
software construct (128 KB of main memory dedicated for the refresh buffer
and the video signal produced by the same circuitry that does DRAM refresh,
just like on BK0010/11)?
   Your textual picture of the MV3100 back panel indicate some switch where
VS3100 has the console switch. Is the switch on MV3100 also for the
console? Does this mean you can convert MV3100 to VS3100? Does this mean
that KA41 has mono video capabilities? But even if it does, how can you
access them? According to your picture, it doesn't have a video DB15. Or
maybe some of the numerous otherwise unused pins on the DB25 are used for
this purpose?
> The layout changed with the MicroVAX 3100-30 upwards.
   MV3100 M30+ is a completely different beast. The lack of support for it
in ULTRIX and NetBSD is one of the consequences of this. BTW, this family
includes some VAXstations (VS4000) as well as MicroVAXen. Are the system
boards the same in these MicroVAXen and VAXstations? I think that VS4000s
always have video on an add-on daughterboard, so the system board should be
the same.
   
   Sincerely,
   Michael Sokolov
   Phone: 440-449-0299
   ARPA Internet SMTP mail: sokolov@alpha.ces.cwru.edu