If necessary, enable support for disks greater than 1 Gbyte.
On the AHA-1530P and AHA-1532P, use the on-board utility (press Ctrl-A at boot time) to select this option from the Advanced Features menu.
On the AHA-1522A and AHA-1520A, set this option by adding a jumper to pin 0 (the rightmost pin) of jumper block J5.