Gerald,

According to information that came with a 30 GB HD that I recently purchased, 
the following BIOS restrictions apply:

   Prior to August 1994:      May not support HDs > 528 MB
   Prior to February, 1996:   May not support HDs > 2.1 GB
   Prior to January, 1998:    May not support HDs > 8.4 GB
   Prior to June, 1999:       May not support HDs > 32 GB

FWIU, virtually all large HDs come with software that will permit you to 
install large HDs in machines with old BIOSes.  Western Digital comes with 
EZDrive.  Other software solutions, collectively known as Disk Drive Overlay 
Software (DDO), include Ontrack's Disk Manager, MaxBlast, etc.  Hardware 
solutions in the form of cards can be obtained from Promise (DriveMax) and 
from Ontrack (or maybe it is Phoenix).

I have had Disk Manager in one machine (a 486/586 machine) for a number of 
years now and have no problems with it.  I believe that a current version can 
be downloaded from Ontrack's web site.

I also have Promise's DriveMax board in another machine (P75).  Cost is 
less than US$20.00 from Dalco.  DriveMax is capable of recognizing HDs up to 
128 GB.  The board installed seamlessly and recognized the 30 GB HD that I 
had installed.  (I have not yet transferred any files to the large HD, so I 
don't know how it will work.)  As you probably know, one of the first things 
that a system BIOS does is look for onboard BIOSes on installed boards and 
loads them automatically, therefore, no additional memory is used.

I *think* that before I can install a DriveMax board in the 486/586 machine, 
I first have to update the system BIOS so that it is capable of accessing 2.1 
GB.

The Linux gurus will have to specifically address whether Linux can access 
large disks without upgrading the BIOS.

HTH

Roger Turk
Tucson, Arizona

Gerald wrote:

. >    Can anyone set me straight on the situation regarding large HDs and
. > (early) BIOS limitations? I seem to remember a limit of 8.4Gb for 486
. > and early 586 BIOSes, but does that mean that HDs > 8.4Gb won't work at
. > all on these motherboards, or will the space above 8.4Gb just be
. > unreachable? I know that one can get special drivers to overcome the
. > limit, but this is going to be for Linux mainly, so the possibility of
. > using a DOS driver doesn't exist.

. >    The problem is that I need a new HD and all I see for sale these days
. > seem to start at around 20Gb. I don't mind buying 20Gb so long as I know
. > that I can use 8.4Gb of it! Any clues or enlightenment, as always,
. > very welcome - thanks!

. >       Gerald.

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