> > I have got the ram installed in the right places so that the eprom monitor
> > diags see it however it now complains that there is no NVROM! Or can't load
> > default settings into it.  There is a empty 24 or 28 pin dip socket in the
> > middle of the mainboard next to the back panel is this where the NOVRAM
> > should be?

You may want to read

http://doener.unix-ag.uni-kl.de/FAQ/eeprom-nvram.FAQ 

or any other copy of the eeprom-nvram.faq (use your favourite search
engine).

I have replaced the 3V battery in such an NVRAM (Mostek MK48T02) chip.
The chip consits of the usual 24 pin case + "backpack". The backpack
houses oscillator and battery. Be careful not to hurt the oscillator
side. I actualy cut the half with the battery off (fine saw blade),
but that is not necessary. From the FAQ (with my conmments):

  Refurbishing the old nvram: 
  ---------------------------
  The contents of the (nv)ram are backed up by a 3V lithium battery.
  It's located together with a quartz on top of the ram in a kind of backpack.
  The battery is on the side that's opposed to the dot marking pin 1,
  next to pin 12:

                         _oscillator
                        /
                       / _battery
                      / /
                   -------
                   | O O | <-- cut here 
                   -------
                  /
             Pin 1

   At the point marked above, some kind of nose is reaching down from the
   backpack over the resin.
   Carefully cut through the polyester resin filling the dimple.
   This works best with some kind of mini drill with a small milling head.
   buried in the resin you'll find two small diagonal metal connectors :).

I grinded carefully with a sharp blade. Try to find the connectors as
high up as possible. That you will give you more place to solder.

   Be careful not to short-circuit them, or you'll loose the contents of your
   nvram (if it was still able to keep them). -That's why you should save them
   *before* :)

After battery replacement my 4/400 could use the NVRAM again (without
reprogramming from my side) The battery was disconnected ~ 5 minutes.

   The connector closest to pin 12 is ground, the other (opposing) one +3V.
   You can now solder some wire to them and connect them to a new 3V lithium
   battery.

I used a "new" battery from a scrap 286 PC. I soldered the wires first
to the battery, then to the NVRAM.

Harald.