Duplidisk 3 gives RAID 1, and no drivers

Duplidisk 3 gives RAID 1, and no drivers: "All ARCO Duplidisk RAID solutions are software independent by design, and in my experience all do their job nicely, 'faking' a single IDE hard disk to the system board, or hard disk controller, while duplicating data on a pair of identical, or similarly sized, IDE disks. You can use different drives, but then the board switches speed to PIO4 (no UDMA), and you will be limited to the capacity of the smaller drive, which always must be the primary."