Subject: VS3100 console switch: random hardware factoid
To: None <port-vax@NetBSD.ORG>
From: maximum entropy <>
List: port-vax
Date: 08/30/1997 16:01:40

I just wanted to report an interesting datum for the record.  I
haven't seen this mentioned in any of the various FAQ's etc. that I've
seen, so I thought mentioning it on this list, and recording it for
posterity in the mailing list archives, might help someone.

I have a few VAXstation 3100's, which I recently got for free.  I
pulled one out of the stack randomly and installed NetBSD on it.  You
can find information about that experience in a previous message.

A few days ago I pulled another one out and was about to install
NetBSD on this box as well.  The first step, of course, was to set it
to use a serial console.  Looking at the back of the machine, I was
stumped.  Where the console switch was on the first machine, there was
nothing on this machine.  I let a day or two go by and then decided to
take a closer look.

The first machine is labeled VS42-AA on the back.  The second is
labeled VS42-BA.

So did DEC decide that VAXstations just don't need a serial console
and remove the switch?  I decided to open up the box and take a look
around inside.

A minute or so of poking around inside revealed the amusing truth.
DEC did evidently decide that these machines don't need a console
switch, so they stopped cutting the hole in the plastic case that
allows you to get at the switch.  The switch is still present, in
exactly the same physical position (directly between the status LEDs
and the COMM port.)

It looked like getting at the switch to change its position would
require almost completely disassembling the machine.  However, it
turns out that you can use a screwdriver to "pry" the plastic back a
little, giving just enough room to stick a pin in there to push the
switch to the up position.  You don't even need to remove the
machine's cover to do it this way!

Keep on hacking,

entropy -- it's not just a good idea, it's the second law.