System BIOS and Hard Drive
Related Questions and Answers


Subject: BIOS
Summary: This is a general discussion of the most commonly asked questions about the system BIOS and its relationship to hard drives. The following will provide you with basic information beginning with the definition of a BIOS, to identifying key features found in various BIOS's. The purpose of this document is to aid you in solving minor difficulties you may be currently experiencing.

Notice: The information provided herein is presented as is and without any warranty of any kind, either expressed or implied. In no event will DEW Associates Corporation be liable to you for any damages, including any loss of profit or other money damages, arising out of the use or inability to use the information contained herein. We make no representations or warranties with respect to the contents hereof and specifically disclaims any implied warranties of merchantability or fitness for any particular purpose. Any parameters and specifications provided are subject to change without notice.


Topics Covered:

  • Definitions of CHS, NORMAL, LARGE and LBA
  • BIOS Limitations
  • MaxBlast Issues
  • Data Transfers and BIOS setting changes

Q01: What is Logical Block Addressing (LBA)?
Q02: What is CHS?
Q03: What is the difference between Normal, LBA or Large mode?
Q04: What is an Enhanced BIOS?
Q05: How is it determined if a BIOS is an Enhanced BIOS?
Q06: What if the BIOS does not support the full capacity of the drive?
Q07: Why use software for translation?
Q08: Can a hard drive be transferred to another computer without losing data?
Q09: Can the translation mode or parameters in the BIOS be changed?

Q01: What is Logical Block Addressing (LBA)?
A01: LBA is a mathematical scheme for addressing sectors, beginning at cylinder 0, head 0 and sector 1, which is equal to LBA 1. This scheme linearly maps the drive until the final physical sector is reached. LBA is efficient because it reduces some system overhead by not having to convert the operating system's LBA to the BIOS CHS and then back to drive LBA.

Q02: What is CHS?
A02: CHS stands for Cylinders, Heads and Sectors, this is the conventional means for BIOS to communicate to the drive. CHS has a limitation of 1,024 cylinders, 16 heads and 63 sectors per track resulting in a maximum capacity of 504 MB.

Q03: What is the difference between Normal, LBA or Large mode?
A03: Normal mode is the standard BIOS translation scheme. This mode does not support drives greater than 504 MB. Large mode is a generic translation scheme used by some BIOS's to access drives up to 1 GB. Logical Block Addressing (LBA) mode is a more advanced method of translation than Large mode. LBA mode is a somewhat faster and can see drives up to 8 GB.

Q04: What if the BIOS does not support the full capacity of the drive?
A04: There are three possible answers to this question:
  • Upgrade the BIOS for the computers motherboard or replace the motherboard.
  • Add an Enhanced IDE card that has its own BIOS that provides support for large hard drives.
  • Install a translation software product such as Maxtor's MaxBlast software, they're latest version is 9.06M.

Q05: Why use software for translation?
A05: Software translation is an effective, although non-conventional, means of translating large capacity hard drives so they can be utilized on older systems with older motherboards and BIOS's. We use Maxtor hard drives almost exclusively, and they (Maxtor) furnish a driver made by StorageSoft, which is called MaxBlast. Instead of loading a driver in the start-up files, MaxBlast loads drivers before the operating system is loaded. 

Q06: Can a hard drive be transferred to another computer without losing data?
A06: Generally speaking no, but there are exceptions to everything. Usually there are no guarantees that a new motherboard's BIOS will use the same translation scheme as its predecessor. We recommend that you back up your data prior to making any system changes. We also recommend that the hard drive be re-partitioned and reformatted once installed in the new system.

Q07: Can the translation mode or parameters in the BIOS be changed?
A07: When a drive is partitioned, the operating system interprets the size of the drive via information provided by the BIOS. Changing the translation can cause permanent data corruption. If the original parameters are changed, they usually cannot be recovered without specialized drive manipulation software. If you do not have this software, we recommend that the hard drive be re-partitioned and reformatted.


Need the Maxtor MaxBlast Software?

How to access the MaxBlast Software:

MaxBlast Version 9.xxM is the only Version of MaxBlast available for electronic download from the Maxtor Internet Site. Due to contractual commitments, Maxtor cannot distribute any other Versions of the MaxBlast software. A copy of MaxBlast Version 9.xxM can be downloaded from the Maxtor Website at: The name of the file to download is MAXBLAST.EXE.


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