G586SP/G586SP AIO
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Large Mode
The Large mode is the extended HDD access mode sup-
ported by the G586SP AIO 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 conver-
sion 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
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.
no.Cylinders
(1024)
x no. Heads
( 225)
x no.Sectors
( 63)
x bytes per sector ( 512)
8.4 Gigabyte
