30
LARGE mode
Extended HDD access mode supported by Award Software.
Some IDE HDDs contain more than 1024 cylinder without LBA support (in some cases, user
do not want LBA). The Award BIOS provides another alternative to support these kinds of
LARGE mode:
CYLS.
HEAD
SECTOR MODE
1120
16
59
NORMAL
560
32
59
LARGE
BIOS tricks DOS (or other OS) that the number of cylinders is less than 1024 by dividing it by
2. At the same time, the number of heads is multiplied by 2. Reverse transformation process
will be made inside INT 12h in order to access the right HDD address the right HDD address!
Maximum HDD size:
no. Cylinder (1024)
x no. Head
( 32)
x no. Sector
( 63)
x bytes per sector ( 512)
1 Gigabytes
NOTE:
To support LBA or LARGE mode of HDDs, there must be some softwares involved. All these
softwares are located in the Award HDD Service Routine (1NT 13h). It may be failed to access a
HDD with LBA (LARGE) mode selected if you are running under a Operating System which replaces
the whole INT 13h.
UNIX operating systems do not support either LBA or LARGE and must set to the Standard mode.
UNIX can support drives larger than 528MB.
3-11 SAVE & EXIT SETUP
The "SAVE & EXIT SETUP" option will bring you back to boot up procedure with all the
changes you just made which are recorded in the CMOS RAM.
3-12 EXIT WITHOUT SAVING
The "EXIT WITHOUT SAVING" option will bring you back to normal boot up procedure without
saving any data into CMOS RAM. All of the old data in the CMOS will not be destroyed.
3-13 I/O & MEMORY MAP
MEMORY MAP
Address Range
Size
Description
00000-7FFFF
512K
Conventional memory
80000-9FBFF
127K
Extended Conventional memory
9FC00-9FFFF
1K
Extended BIOS data area if PS/2 mouse is
installed
A0000-C7FFF
160K
Available for Hi DOS memory
C8000-DFFFF
96K
Available for Hi DOS memory and adapter ROMs
