So the problem and the solution were in the EZ-Setup program I use to get
the right outmap of a 2,5Gb western hardrive. (This is old BIOS so the
table needs to be correctly translated).
Whenever installed it overrides e'thing in the first 63 sectors, even other
bootselectors.

It turned out that the disklabel was erased (somehow).

Solution:
Booted with the flops-> sysutils->fdisk to put the right id (169) on the
root partition ->
automagically ended the misery and the boot went just fine.

Doh, the smallest things overlooked.

T@W

Original message:
>Hi,
>
>after some problems with the MBR (thanks to OS-BS) root suddenly lost its
>mountpoint.
>The boot goes as far as:
>"root on wd0a dumps on wd0b
>no file system for wd0 (dev 0x0)
>cannot mount root, error= 79
>root device(default  wd0a"} (which is the right partition to look for),
>but can't find the mounting point so now way to get to the contents.
>And that was it. Alas I have no alternate root.
>I know everything is still there, partitions are right but wrong bootstrap
>so no way to get into the tree. (remind me never to use that disk for
>multiple OS'es ......ever).
>(I regret not to have backed up that foolish first 63 sectors).
>
>Am I fried now? There's surely a way to get the data out or even get it
>back into good health.........or isn't there?
>
>Any help to rescue those orphans much appreciated.
>
>Cheerz,
>Touchwood
>PS I still can install OS-BS or any other bootselector