User`s manual

G586OPC
75
Large Mode
The Large mode is the extended HDD access mode
supported by the G586OPC system board. Some IDE
HDDs have more than 1024 cylinders without LBA
support (in some cases, you may not want the LBA
mode). The system board provides another alternative to
support these kinds of HDD.
The BIOS tells the operating system that the number of
cylinders is 1/2 of actual and that the number of heads is
double the actual. During the disk access, the reverse
conversion is done by the INT13h routine.
Example of Large mode:
CYLS. HEADS SECTORS MODE
1120 16 59 NORMAL
560 32 59 LARGE
Maximum HDD size:
no. Cylinders (1024)
x no. Heads ( 32)
x no. Sectors ( 63)
x bytes per sector ( 512)
1 Gigabyte
Note:
To support LBA or Large mode, address translation
software is included in the Award BIOS HDD Sevice
Routine (INT13h). If you are running an operating
system that bypasses the BIOS Int13 Service Routine,
LBA and Large Mode may fail.