MicroVAX 3100 Questions.

[Michael Sokolov]

Scott Stevens <chenmel at earthlink.net> wrote:

> 1.  I notice on the Web that there is quite a bit of info about
> MicroVAX 3100 systems.  I also see that there are a variety of models.
> Is there an easy way to figure out which one I have?

Power it up with a terminal connected to the console port, write down what
it scribbles on the console on power-up, and post it to the list.  One of
the lines (the one starting with KA) identifies the system board.

> 2.  Would it be possible and/or work to replace the tape drive with a
> SCSI CD-ROM reader?  I don't have a source for tapes.

Look for one that can be set to 512 byte block mode.

> 3.  Is it worth putting VMS on this box?

That's only for you to decide for yourself.  What OS do you want to run?
Do you want VMS or UNIX?

> Is there a flavor of vintage UNIX that I could put on the system?

I'm pretty close to getting 4.3BSD-Quasijarus to run on it.  Just need to
write the SCSI code.

> 4.  What is the console on this hardware?  It has the three serial
> ports on RJ-type connectors, and from what I gather this is a TTY-only
> machine, no framebuffer, etc.

You are correct, except that the connectors are not RJ but DEC423 MMJ.  In
normal operation port 1 is the console.  There is also an "alternative
diagnostic console" mode enabled by a switch on the back that moves the
console to port 3 and makes the CPU halt on line break.

> 5.  Is there a thorough hardware reference for this machine out there
> on the net that I should get?  I looked on the HP/Compaq site, and it
> appears that they pay a small amount of  homage to the system, but
> without much substancial info.  A hardware reference manual in PDF
> would be great.

Unfortunately it's a completely undocumented machine.  DEC never published
a real technical manual for it, only screwing/unscrewing guides for failed
servoids.

MS