5MVP3
MVP3 Main Board
55
3. 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. A
reverse transformation process will be made inside int 12h in order to access the
right HDD address the right HDD address!
4. Maximum HDD Size:
No. Cylinder (1024)
X No. Head (32)
X No. Sector (63)
X No. Bytes Per Sector (512)
1 GB
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 (int 13h). It may be failed to access a HDD with LBA
(large) mode selected if you are running under an perating system which
replaces the whole int 13h. Unix operating systems do not support either LBA or
large and must utility the standard mode. Unix can support drives larger than
528MB.
