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Normal Mode
The Normal mode is the generic access mode in which neither the
BIOS nor the IDE controller will make any transformations during hard-
drive access.
The maximum number of cylinders, heads and sectors for Normal mode
are 1024, 16 and 63, respectively.
no. Cylinders
(1024)
x no. Heads
( 16)
x no. Sectors
( 63)
x bytes per sector
( 512)
528 megabytes
If you set your HDD to Normal mode, the maximum accessible HDD will
be 528 megabytes even though the physical size of the HDD may be
greater than that.
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 HDD accessing, the IDE controller will transform the logical ad-
dress 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
( 255)
x no. Sectors
( 63)
x bytes per sector
( 512)
8.4 gigabytes