I, too am having trouble with the boot floppy for NetBSD-1.6/sparc.
As I've seen mentioned, on my SS5 (openboot 2.x), 'boot floppy'
complains about bad magic number and that it couldn't find Sun
disklabel.

This is curious because I used exactly the same image when creating
a bootable (multiboot) CD-ROM and it works just fine.

If I boot from CD-ROM or tape, I can load the instfs.tgz from the
second floppy just fine.

I've created the floppies both on an NetBSD-1.5/i386 system and on
NetBSD-1.6/sparc and the ".../floppy/disk1"  or ".../bootfs/boot.fs"
image fails to boot.

The NetBSD-1.5.3 floppy set works just fine, though.

-- 
John D. Baker                               johnbaker(at)ev(one)(dot)net
OpenBSD        NetBSD        Darwin/MacOS X        FreeBSD        BSD/OS
BSD -- The Operating System for the Third Millenium and Beyond!