Upgrading early BIOS - Drive Overlay

[Michael Lee]

Remember there were also the utilities to fool the PC into using larger 
sized disks, but I never liked those at all.  Most hard drives in that 
time period came with the Ontrack, EZDrive, Disk Manager, MaxBlast, 
programs.  The Disk Drive Oveylay programs do a software convert of the 
BIOS settings and actual settings and make it boot/work, usually.  These 
altered the MBR to sit there, and these have their issues and were 
always a last resort.  The drives do NOT swap into other machines well, 
and any issue, esp with the MBR would pretty much cause a FAIL.



Eric J Korpela wrote:
> BIOS for early 486 machines usually included two user defined disk
> types, often the highest numbered types (maybe 47 and 48).  These
> allowed you to enter the number of cylinders heads and sectors.  You
> might not to be able to enter the actual geometry for your drive.
> You'll probably be limited to 16 heads, 63 sectors and 1024 cylinders
> (504MiB).
>
> Whatever OS you install may be able to read the full disk capacity
> from the drive and use it all (ignoring the BIOS settings), but all
> files needed for booting will need to be below the 504 MiB boundary.
>
> Eric
>
>
>
> On Sun, Aug 10, 2008 at 2:11 PM,  <Hollandia at ccountry.net> wrote:
>   
>> One of my machines is an old Packard-Bell Legend 610 machine, to which I am
>> trying to fit a second hard drive.
>>
>> The machine will not recognize any modern (or semi-modern) hard drive I have
>> attempted to fit. I have tried various master/slave combinations, to no avail.
>>
>> My guess is that this is due to the BIOS being of am early type. The BIOS
>> chip is a socketed DIP package and the lettering on it is too faded to read.
>> The screen boot-up display is this:
>>
>> PhoenixBIOS(TM) A486 Version 1.01
>> PB400 OPTI 486WB
>> Reference ID 08
>>
>> Is this a reasonable guess?
>>
>> If so, what might be done by way of a BIOS upgrade?
>>
>> Thanks,
>>
>> Kurt
>>
>>
>>