Try disabling everything unnecessary in the bios.
A bit hard - the first motherboard has no built-in LAN, IDE, sound, floppy, serial/parallel. No built-in peripherals, so nothing to switch off
But the mystery is partly solved. I tried booting the system from CD, and chose to install. That resulted in a no drives found message. I tried connecting a random harddrive instead of the flash drive, and then there is a harddrive available for installation.
Then I noticed that the ad0 line is missing from dmesg when the flash drive is connected. The BIOS finds it, and FreeBSD can boot from it, but not find it
The drive is an M-Systems IDE flash drive - not a Disk-on-Chip or some other M-Systems weirdness. I guess I should buy a PQI 32MB IDE module - those usually work...
Best regards,
Mikkel C. Simonsen