Fresh install won't boot

[Dave Sill <ds-openbsd_(_at_)_sws5_(_dot_)_ctd_(_dot_)_ornl_(_dot_)_gov>]

Newbie alert!

I just installed 2.5 on a 90 Mhz Pentium--not shared with any other
OS's, though the system previously has DOS and NT dual booting.

The boot disk is a 2 GB Fireball. The active partition, which is
sector 63 to the end of the disk, is devoted entirely to OpenBSD. I
gave it 1.5 GB for root, 100 MB swap, and the rest to /home. I
installed via FTP from the CD-ROM. The install went smoothly, but
after I halted and tried to boot, it hung at the following message,
right after the BIOS listed the disks:

    Using drive: 0 Partition: 3

I booted from the floppy, made sure partition 3 was the active
partition, and ran installboot:

    fsck /dev/wd0a
    mount /dev/wd0a /mnt
    /usr/mdec/installboot -v /mnt/boot /usr/mdec/biosboot wd0

But that didn't help.

Any advice would be appreciated.

-Dave