Due to my own stupidity I managed to overwrite my /dev/root device using dd (don't ask).

Current state is
- Have current backup created using cpio (command used was 'find . -mount -depth -print|cpio -ocB > $TAPE')

- Once I realised what was happening powered off the server but this was too late

- Have a set of boot floppies and have booted off them

- Have mounted /dev/hd0root and run fsck so it is "fixed"

- It is pretty empty (no surprise) but does have unix and unix.old, /etc only has default in it

- The emergency floppies are old and /dev/Stp0 doesn't point to the tape drive we use for backup (DAT)

What I need to work out is how to restore /dev/root from the backup.

Thanks in advance.

How does it go.... he who play in root eventually kill tree.

Re-install the operating system, add the tape drive, make new boot floppies, then restore the root file system from the backup.

Thanks to jgt for at replying but that was not required. Was able to repair and get server all sorted with no data loss. Will post a more detailed description here later for other people to refer to.