DFI G586IPC User Manual page 38

LBA (Logical Block Addressing) Mode
The LBA mode is a HDD accessing method to overcome the 528 mega-
byte limitation. The number of cylinders, heads and sectors shown on
the screen may not be the actual number for the HDD.
During the HDD accessing, the IDE controller will transform the logical
address described by the sector, head and cylinder number into its own
physical address inside the HDD.
The maximum HDD size supported by the LBA mode is 8.4 gigabytes. It
is obtained by the following formula.
Large Mode
The Large mode is the extended HDD access mode supported by the
G586IPC system board. Some IDE HDDs have more than 1024 cylin-
ders without LBA support (in some cases, you may not want the LBA
mode). This system board provides another alternative to support these
kinds of HDDs.
The BIOS tells the operating system that the number of cylinders is half
of the actual number and that the number of heads is double the actual
number. During disk access, the reverse conversion is done by the
INT13h routine.
Example of Large mode:
38
no. Cylinders (1024)
x no. Heads ( 225)
x no. Sectors ( 63)
x bytes per sector ( 512)
8.4 gigabytes
CYLS. HEADS SECTORS MODE
1120 16 59
560 32 59
NORMAL
LARGE