I'd like to thank all who replied. It turned out that
resetting the parameter ram (command-option-P-R held
down through three beep cycles) made the machine so
it would now recognize command-option-O-F (held down
from the chime until I reached OFW). It boots the 1.6 ISO
image just fine (no floppy drive) and some day soon I
plan to overwrite the hard disk with NetBSD. Once I'm
done I think I'll write everything up in a single post.
A lot of the stuff I found by Googling was tentative or
not directly applicable, although helpful as hints.

-----Original Message-----
From: Henry B. Hotz [mailto:hotz@jpl.nasa.gov]
Sent: Wednesday, March 05, 2003 4:50 PM
To: Duncan Missimer; 'port-macppc@netbsd.org'
Subject: Re: PB3400c & OFW secret sauce


At 12:49 PM -0800 2/19/03, Duncan Missimer wrote:
>What's the trick to getting to Open Firmware in a PowerBook
>3400c? I've tried holding down option-apple-O-F before hitting
>the power button, or jabbing them immediately after the chime
>sounds, but it goes to MacOS each time.

Early PowerBook's don't seem to handle the magic salute properly.  I 
know my PDQ was not dependable in that respect.  Try getting a copy 
of systemdisk from Apple.  (There's a cross reference in the FAQ.)
-- 
The opinions expressed in this message are mine,
not those of Caltech, JPL, NASA, or the US Government.
Henry.B.Hotz@jpl.nasa.gov, or hbhotz@oxy.edu