    Freetech P5F85/87 motherboard BIOS Rev. 11/24/1998
    with patch J.3 for Cx MII, AMD K6-2+ and K6-III+ support,
    and for IDE HDDs up to 128GB (32GB bugfix).
    05/29/2026
    by Jan Steunebrink

The latest, and probably final, BIOS upgrade from Freetech for the P5F85/87
is the 11/24/1998 version (P5F87-10.BIN).
This BIOS does not support the (mobile) K6-2+/III+ CPUs.
Also the Cyrix MII CPUs with 4.0x multiplier are not supported.
In addition the original K6-2CXT/K6-III is not fully supported because this
BIOS doesn't support the 6.0 multiplier for these AMD CPU models.

To overcome these problems, I have patched the 11/24/1998 BIOS to include
proper recognition and handling of the MII, K6-2CXT/K6-III, and K6-2+/-III+.
I've made the following changes:
- Added detection of the Cyrix MII when set to 4.0x multiplier
- Added detection of the K6-2+ and K6-III+ CPUs
- Expanded the CPU Type display routine for correct display of the
  AMD-K6(tm)-2+ and AMD-K6(tm)-III+ strings
- Changed the K6 Write Allocation feature to work also on the K6-2+/K6-III+
- Expanded the K5/K6 busspeed/multiplier/CPU speed detection to work for the
  K6-2+ and K6-III+ as well.
- For K6-2CXT/K6-III/K6-2+/K6-III+, CPU speed support for 5.5 x 83 (457Mhz),
  and for all 6.0x multiplier/busspeed combinations upto 500MHz (6.0 x 83)
  is added.
- Changed the BIOS Setup Default for the System BIOS Cacheable options to
  Disabled. The K6-III and K6-2+/K6-III+ need this setting to run properly.
- Expanded the CHIPSET FEATURES SETUP menu's CPU Core Voltage selections.
  Instead of a single set of 2.8V/2.9V/3.2V/3.3V/3.5V/2.1V/2.2V, two sets
  with 2.0V/2.1V/2.2V/2.3V/2.4V/2.5V and 2.8V/2.9V/3.0V/3.1V/3.2V/3.3V/3.5V
  selections are now available. The BIOS automatically selects one of the
  sets depending on the installed CPU.
  In addition, the Auto Vcore for the K6-III is corrected from 2.2V to 2.4V,
  and for the K6-2+/III+ the correct 2.0V is now supplied in Auto.

In addition I have made a patch to remove the 32GB harddisk limit bug, and
made another patch to remove two additional 64GB limit bugs.
This patched BIOS supports now IDE drives upto 128GB and allows drives upto
640GB to be attached, although the BIOS will then only 'see' the first 128GB.
After booting to a suitable OS (WinXP+SP1 or later, Vista, Linux+kernel 2.4.19
or later) the whole drive upto 640GB can be used, provided all the bootup code
is present in partition(s) below the 128GB boundary.

For all other functions, the patched BIOS is identical to the original 11/24/98,
so you don't have to clear the CMOS if you upgrade from this BIOS.

The filename of the patched BIOS is P5F87_J3.BIN and you can flash it with
the flash program you normally use to flash a P5F85/87 BIOS upgrade.
Please take the usual precautions when flashing your BIOS.

Note that, although this patched BIOS has been tested on different P5F85/87
systems without any problems, it is provided "as is" and you use it
at your own risk.

I like to thank everybody who participated in testing this BIOS.
Jan.

Homepage: http://www.steunebrink.info/
E-mail  : J.Steunebrink@net.HCC.nl

------------------------------------------------------------------------------
Revision history patched Freetech P5F85/87 Ver '10' BIOS:

05/29/2026 patch J.3 release
- Changed the CPU Core Voltage selection menu into two sets. One 2.8V-3.5V
  menu for high Vcore CPUs, and a second 2.0V-2.5V menu for low Vcore CPUs.
  The low Vcore settings are automatically selected when an AMD K6 model 7,
  K6-2, K6-III, K6-2+, or K6-III+ CPU is installed.
- Changed the Auto Core Voltage selection for the K6-III from 2.2V to 2.4V,
  and for the K6-2+/III+ the correct 2.0V is now selected.

01/22/2022 patch J.2; released for beta testing only
- Added support for the Cyrix MII when set to 4.0x multiplier
- Added K6-2CXT, K6-III, and K6-2+/K6-III+ support, including Write-Allocation
  and support for all 6.0x multiplier/busspeed combinations upto 500MHz.
- Updated the 32GB HDD limit bugfix so IDE drives up to 640GB can be atached.
- Fixed a second 64GB limit bug so the IDE HDD Auto Detection menu selection in
  the BIOS doesn't hang anymore on >64GB drives.

10/31/2021 patch J.1; not released, for testing only
- fixed the 32GB HDD limit bug for 64GB IDE drive support.
- fixed the first 64GB HDD limit bug for 128GB IDE drive support.
