Excerpts from netbsd: 27-Jan-98 Re: Problems booting from S.. Dominic J
Hulewicz@inta. (1335*)

> Here's the pfdisk output if that helps any:
> 
>   pfdisk> # Partition table on device: 0
>   geometry 1021 64 32 (cyls heads sectors)

That's it. The Adaptec translates the geometry
to a fake one with 32 sectors/track while the
MBR partition entries are made for 63 s/t.
The bad news is that you have to repartition
and reformat your disk if you can't change this
mapping in the Adaptec BIOS at least a bit.
The reason is that your NetBSD partition starts
in cyl 0, head 1, sector 32 in terms of the
Adaptec geometry, this is the last sector on this
track. The bootloader tries to load 15 consecutive
sectors beginning at this one - this will not work.
You should start the NetBSD partition at sector
32, ie cyl 0, head 1, sec 1.

best regards
Matthias