Seagate BARRACUDA ATA FAMILY ST320430A - Manual (Page 26)

22 Barracuda ATA Family Installation Guide, Rev. A
Figure 5. Alternate Capacity Jumper
2. Move the jumper on the alternate-capacity jumper, as shown
in Figure 5. This causes the drive to appear to your BIOS as
having a 2.1-Gbyte capacity (4,092 cylinders, 16 heads, 63
sectors per track). You may need third-party partitioning soft-
ware, such as Disk Manager, to achieve full capacity of the
drive.
1 3 5
2 4 6
7
8
Full capacity
Limit capacity to 2.1 Gbytes
(4,092 cylinders)