Because the floppy disk driver doesn't tell the kernel it is using
those ports.
>Q2) Apparently there are standard addresses for 3rd & 4th IDE channels at
>168 and 1e8. Should another two major device numbers be added to support 4
Yes.
>or do you feel four IDE devices is enough?
Heck no. I have five SCSI drives on my system, and see no reason I
shouldn't be able to have a similar number of IDE drives.