BIOS SETUP
TF-486 / 27
There are four hard disks listed: “Primary Master”, “Primary Slave”, “Secondary Master”
and “Secondary Slave”. For each IDE channel, the first device is the “Master” and the
second device is “Slave”. Hard disk types from 1 to 45 are the standard one. To
select or change the configuration, move the cursor to the desired position and press
<Page Up> or <Page Down> to change the option.
The AWARD BIOS supports three HDD modes: NORMAL, LBA and LARGE.
NORMAL mode : This is a Generic Access mode in which neither the BIOS nor the IDE
controller will make any transformation during the accession. The maximum HDD size
is supported by the NORMAL mode that is 528 Megabytes.
LBA mode : This is a Logical Block Addressing mode which is a HDD accessing method
to overcome the 528 Megabytes restriction. The number of cylinders, heads and
sectors that are shown in setup may not be the physical number contained in the HDD.
During the HDD accessing, the IDE controller will transform the logical address that is
described by the cylinder, head and sector numbers into its own physical address as
contained inside the HDD. The maximum HDD size that is supported by the LBA mode
is 8.4 Gigabytes.
LARGE mode : Some IDE HDD contains more than 1024 cylinders without the LBA
support. This access mode tricks DOS (or other OS) with the number of cylinders that
is less than 1024 by dividing it by 2. At the same time, the number of heads is multiplied
by 2. A reverse transformation process will be made inside INT13H in order to access
to the right HDD address. The maximum HDD size that is supported by the LARGE
mode is 1 Gigabytes.
Note : 1. To support LBA or LARGE mode, there are softwares located in the AWARD
HD Service Routine“INT13H”. It may fail to access a HDD with LBA or
LARGE modes selected if you are running under an Operating System that
replaces the whole INT13H service routine.
2. Entering incorrect drive specifications will result in a hard disk drive that will
function improperly or no function at all.