Excerpt from sucho2 <sucho2@vt.edu>:

  disklabel -e wd0

  this will bring the vi to edit your partition table.  You'll note that at the
  bottom, there is that unallocated slice you've left for /home which is marked
  "unknown" or something like that

I thought one got something like ed (?) when running disklabel -e wd0, but then
I was booting from CD.  I got a three-digit number followed by the cursor at the
next line, then was completely lost.  All I could think of was to type q, and
that got me out (good guess).  But now I think I can use mbrlabel, having
downloaded that man page.  I also downloaded the man page for ed, still find it
very difficult to follow.

Reason for this is when I boot from hard disk, I type r at login prompt, and
before I have a chance to type further, get 7 more r's followed by 
pckbc: command timeout, then 9 more r's on the next line, then a Password:
prompt on the next line, but since there is no response to the keyboard, I can't
do anything except Reset button.  Could this be because of missing fields in
/etc/fstab?  I managed to mount an msdos-formatted floppy and copied fstab to
the floppy for editing in elvis or vim (Linux, though possibly the DOS port 
might also work), then I can copy back.

Why do they use ed for the text editor, when vi is more of a Unix standard and
a little less user-hostile?  Or maybe something comparable to the Tiny Editor
of DOS and OS/2, written by Tim Baldwin of IBM and much smaller than ed?  Or at
least there could be a text file indicating how to use ed.   

I forgot to say earlier, NetBSD version in question is 1.5.2 i386.