protech PC-550, User Manual, Page: 78 / 106

Chapter 5 Award BIOS Setup
Page: 5-20
PC-550 USER
′
S MANUAL
LARGE mode:
Some IDE HDDs contain more than 1024 cylinder without LBA support (in
some cases, user do not want LBA). The BIOS provides another alternative to
support these kinds of HDD.
CYLS HEADS SECTOR MODE
-----------------------------------------------------------------
1120 16 59 NORMAL
560 32 59 LARGE
BIOS tricks DOS (or other OS) that the number of cylinder 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 13h 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
no. Per sector ( 512)
---------------------------------------
Total: 1 Giga byte
REMARKS:
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 a Operating System which replaces the whole
INT 13h.