I've been trying to install NetBSD on one of my Indy's for some
months now, and it all comes down to:
  "I can't get a serial console working."

I've seen the recent FAQ on serial consoles, and built a serial
cable according to the pinouts listed for an 8-pin MiniDIN SGI
to DB9.  I then tested the pinouts with an ohmmeter after the soldering.

Some time ago I enabled serial console in the PROM (from the system
maintenance menu)  as well as in /etc/inittab.  Since I did that, I
don't
ever see the system maintenance menu button.  Here is what I do,
-  Disconnect keyboard on the Indy
-  connect the serial cable
-  fire up minicom, 9600 8N1
(tried other port when com1 didn't work, also attempted with window$
terminal)

Wait.    The machine boots up to xdm, and after I plug in the keyboard,
works normally, but still running IRIX (not what I wanted).

Is there some sequence of commands that I need to execute to
get the serial interface to work?   Is minicom the wrong choice?

I've scanned NetBSD.org  for more info on several occasions but
never found much until the recent "serial console faq", but that
still didn't get me there.

Any ideas?