[sorry for not PR'ing this I don't have a NetBSD system up and running
right now]

Ok, I've tried most of the available boot13_ALPHA floppies to
"upgrade" a machine here (so I don't have to try and re-work the
geometry to save the DrOS partition).

The floppy on ftp.netbsd.org and Havard's latest, both have the fsck
fix so that one does not get a mount_ffs usage message, but otherwise
the result is the same as previously noted:

It fsck's /dev/rwd0a
copies fsck

fails to re-mount /mnt read-only
/dev/wd0a: file system not clean; please fsck(8)

and its down hill from there...

several errors from fsck followed by a segmentation fault and game
over.

I'm going to try and upgrade this machine manually as it is currently
hosed anyway. 

--sjg