On Sun, Nov 18, 2007 at 05:54:40AM -0700, John R. Shannon wrote:
> On Sunday 18 November 2007 05:40:07 am John R. Shannon wrote:
> > On Sunday 18 November 2007 05:37:00 am John R. Shannon wrote:
> > > Following an installation, from CD, where I selected the option to update
> > > the MBR,  the computer won't boot and displays an Operating System Not
> > > Found message.
> > >
> > > fdisk -v sd0 shows:
> > >
> > > 0: NetBSD (sysid 169)
> > >     start 12, size 71687360 (35004 MB, Cyls 0/1/5-746743/5/4), Active
> > >         beg: cylinder    0, head   1, sector  1
> > >         end: cylinder 1023, head  11, sector  8
> > >         PBR is not bootable: Bad magic number (0x0000)>
> > >
> > > Running :
> > >
> > > installboot -v /dev/rsd0d /boot/bootxx_ffsv1
> >
> > That was:
> >
> > # installboot -v /dev/rsd0d /usr/mdec/bootxx_ffsv1
> > File system:         /dev/rsd0d
> > Primary bootstrap:   /usr/mdec/bootxx_ffsv1
> > Preserving 51 (0x33) bytes of the BPB
> > Boot options:        timeout 5, flags 0, speed 9600, ioaddr 0, console pc

I'm not sure what you have managed to write where!

Sector zero of the disk should contain one of /usr/mdec/mbr*
The first sectors of the netbsd mbr partition should contain
/usr/mdec/bootxx_ffsv1 (with the netbsd disklabel replacing the 512
byte gap).

So your installboot command ought to specify /dev/sd0a (or rather the
netbsd ptn at the start of the mbr ptn) not /dev/rsd0d (which is the
start of the disk).

Possibly there are problems caused by the small number of sectors per
track. 12 is rather unusual!

You could look at the start of the disk to see what is present.
To fix it you may need to reinstall the mbr and pbr bootcodes.
'fdisk -c /usr/mdec/mbr sd0' should re-add the mbr code, and
instalboot specifying sd0a the pbr code.

	David

-- 
David Laight: david@l8s.co.uk