Multitech MultiVOIP MVPGK1 Gatekeepers, Hardware User'S Manual

Page: 79 / 87

80
MultiVOIP Gatekeeper User Guide
x no. Sector ( 63)
x no. Bytes per Sector ( 512)
———————————————————-
Total:
528 megabytes
If the user sets the HDD to NORMAL mode, the maximum accessible HDD size will be 528 Megabytes
even though its physical size may be greater than that.
LBA (Logical Block Addressing) mode:
This new HDD accessing method overcomes the 528 megabyte bottleneck. The number of cylinders,
heads and sectors shown in Setup may not be the number physically contained in the HDD.
During HDD accessing, the IDE controller will transform the logical address described by the sector,
head, and cylinder numbers into its own physical address inside the HDD.
The maximum HDD size supported by LBA mode is 8.4 gigabytes, which is obtained by the following
formula:
x
no. Cylinder (1024)
x no. Head ( 255)
x no. Sector ( 63)
x no. of Bytes per Sector ( 512)
———————————————————-
Total:
8.4 gigabytes
LARGE mode:
Some IDE HDDs contain more than 1024 cylinder without LBA support (in some cases, users 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
The 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 13h in order to access the right HDD address.
Maximum HDD size in Large Mode:
x
no. Cylinder (1024)
x no. Head ( 32)
x no. Sector ( 63)
x no. Per sector ( 512)
—-——————————————————
Total:
1 gigabyte
Note: Support of the LBA or LARGE mode of HDDs, requires some special software. All such software packages are
located in the Award HDD Service Routine (INT 13h). If the PC is running under a Operating System that replaces the
whole INT 13h, that PC may fail to access a HDD set to LBA or LARGE mode.
HDD Low Level Format
If you choose HDD LOW LEVEL FORMAT from the CMOS Setup Utility menu, the following screen will
appear: