Hello Frederick!

  AB> If I'm correct, fdisk partition '0' is the whole disk
    > minus the boot track.

  FB> No, it's the whole disk; disklabel "d" is the whole
    > disk, too, and "c" should be the whole disk minus one
    > track.

It was the 'start 46' part that made me think it had skipped
the boot track.

  FB> Are you sure NetBSD can utilize that last cylinder? If
    > not, it may not fail until the disk is nearly full.

The trial read and write you suggested seemed to work.  I
wonder if I put 902 in the CMOS setup program by mistake.
I'll check that.

Regards,
  - Andy Ball.