dd if=/dev/zero of=/tmp/flash.img bs=512 count=250880
~/nbsd/O/sbin/fdisk/fdisk -t disktab -T blah -0 -f -u -s 169/63/125377 /tmp/flash.img
~/nbsd/O/sbin/fdisk/fdisk -t disktab -T blah -1 -f -u -s 169/125440/125440 /tmp/flash.img
~/nbsd/O/sbin/fdisk/fdisk /tmp/flash.img
~/nbsd/O/sbin/fdisk/fdisk -t disktab -T blah /tmp/flash.img