Hard disk and the seven major BIOS limitations (I)

Part I

1- Systems with BIOS dated prior to July 1994 (504 MB {binary} / 528 MB {decimal} Limitation).

Typically these BIOS will have a 504 MegaByte (1,024 cylinder) limitation. Prior to this date, most MotherBoard Manufacturers' BIOS did not provide the Logical Block Address (LBA) feature needed for proper translation. Some BIOS had LBA mode in the Bios Setup, but the feature did not work properly.

126855 - Windows Support for Large IDE Hard Disks:

122052 - Logical Block Addressing (LBA) Defined: LBA is a run-time function of the system BIOS.

2- Systems with BIOS dated after July of 1994 (2.048 GB Limitation).

Typically, these BIOS provide support for HD Drives with capacities larger than 504 MegaBytes. However, depending on the Manufacturer's release date and version number, different limitations may be encountered. The major limitation is the 4,093-4,096 cylinder limitation. This barrier is derived from the fact that some BIOS Manufacturers implemented Logical Block Addressing (LBA) translation in their BIOS with a 4,093 - 4,096 cylinder limitation. System hangs would occur when the cylinder limitation threshold is exceeded. A System hang is defined when the Operating System hangs during initial loading, either from Floppy Diskette or existing HD Drives. If these symptoms of System hang occur or there are questions whether the system BIOS will support the HD Drive, contact the System or MotherBoard Manufacturer for assistance.

127851 - Problems Accessing FAT16 Drives Larger Than 2 GB:

DOS - The DOS operating system has a 2.048 GB per drive letter (e.g., C:, D,: E barrier, also has an 8.4 GB total drive capacity barrier.

Windows 95A (FAT-16) - The Windows 95 (FAT 16) operating system has a 2.048 GB per drive letter barrier. See: Win9x Versions.

OS/2 using FAT-16 - The OS/2 using FAT 16 operating system has a 2.1 GB per drive letter barrier. Older versions of Warp cannot address drive capacities greater than 4.2 GB. User's MUST contact IBM for possible Driver Pack Upgrades to bypass this limitation.

3- The 4.2 GB Limitation (FAT16).

The maximum parameters at the 4.2 GB barrier are 8,190 cylinders, 16 heads and 63 sectors for a capacity of 4.2 GB. A system hang is defined when the Operating System stops responding during initial loading, either from Floppy Diskette or existing Hard Drives. This can be caused by the BIOS reporting the number of heads to the operating system as 256 (100h). The register size DOS/Windows 95 uses for the head count has a capacity of two hex digits. This is equivalent to decimal values 255. If these symptoms of system hang occur or there are questions whether the system BIOS will support the drive, contact the system or motherboard manufacturer for assistance.

118335 - Maximum Partition Size Using FAT16 File System:

Windows NT 4.0 using FAT-16 - Windows NT 4.0 using FAT 16-File System has a 4.2 GB limit. Hard drives greater than 4.2 GB will require multiple partitions if using the FAT 16 File System.

4- The 8.4 GB Limitation - January 1998.

The maximum parameters at the 8.4 GB barrier are 16,383 cylinders, 16 heads and 63 sectors for a capacity of 8.455 GB. To go beyond this boundary, a new extended INT 13 function [extended BIOS functions] is needed from the BIOS as a support feature for the drives. Even though a BIOS is dated correctly or is the current version, it may not be able to support extended interrupt 13 because of modification done to the "CORE" of the BIOS from the MotherBoard Manufacturer.

153550 - Hard Disk Limited to 8-GB Partition: "This behavior can occur if the Hard Disk Controller does not fully support the interrupt 13 extensions. This information applies to both IDE and SCSI hard disk drives."

197667 - Installing Windows NT on a Large IDE Hard Disk: 

Escrito por Jose Pinto às 17h39  em 3 de junho de 2007