> When I choose the option  "Install NetBSD to hard disk," I get the message:
> "I can not find any hard disks for use by NetBSD. You will be returned to
> the original menu.", but there are 2 SCSI-disks in the computer.

Is your SCSI adapter recognized by NetBSD?

> 
> Can somebody tell me what I can do to fix this problem?

Please post here your dmesg (that's the green messages printed at
startup). You can recall it by pressing Ctrl-Alt-Esc, then typing dmesg
(and then typing c when you are done).

As this would be quite difficult to copy manually, I'd suggest to do the
install using a serial console and capture the output.

(Ask if you don't know how to do it.)

Bye	Pavel