Excerpts from netbsd: 13-Dec-97 Re: installboot doesn't see.. Paul
Newhouse@newhouse.b (785)

> >What does fdisk report on the disk?
> 
> Crap.

(I'm assuming that you used "fdisk /dev/rxd0d".)
Then there was simply no MBR present.
You can install one with "fdisk -i", or use a
boot selector program.

> You should try to start the 
> >a-partition at offset 0, if at all possible.  It looks like BIOS
thinks, the 
> >a-partition starts at 0, because the NetBSD partition (c/d) starts there.

There are stupid BIOSes out there which hang up at startup
if the partition table contains an entry starting at 0.
(endless recursion?)
However, it's worth a try. (but you lose your 'a' partition)
The other way is to edit the MBR partition table by
"fdisk" and set the start sector to the real beginning of
partition 'a'.
"installboot" doesn't care about 'c' or 'd', it installs at
the beginning of the partition you specify. (This is
different from the old "disklabel" behaviour.)

best regards
Matthias