    BIOSTAR 8500TTD motherboard BIOS TTD0616B (06/11/98)
    with patch J.3 for Cx MII, AMD K6-2CXT, K6-III, K6-2+ and K6-III+ support,
    and for IDE HDDs up to 128GB (32GB bugfix).
    09/01/2025
    by Jan Steunebrink

The latest, and probably final, BIOS upgrade from BIOSTAR for the TTD8500 is
version TTD0616B. This BIOS does not support the (mobile) K6-2+/III+ CPUs.
Also the original K6-2CXT / K6-III, and Cyrix MII CPUs with 4.0x multiplier,
are not properly supported.

To overcome these problems, I have patched the TTD0616B 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 K6 Write Allocation feature to work also on all K6-2/III CPUs
  with the CXT core and enabled this feature for the K6-2+ and K6-III+ as well
- Expanded the CPU Type display routine for correct display of the AMD-
  K6(tm)-III, K6(tm)-2+, and K6(tm)-III+ strings
- Added 6.0x83 (500MHz), 5.5x83 (458MHz), 6.0x75 (450MHz), and 5.5x75 (412MHz)
  support for the K6-2CXT, K6-III, K6-2+ and K6-III+
  Deleted the unused 350MHz (3.5 x 100) support to make room for this change.
- Set the BIOS Setup Defaults for the Video and System BIOS Cacheable options
  to Disabled. The K6-III and K6-2+/III+ need this setting to run properly.

In addition I have made a patch to remove the 32GB IDE harddisk limit bug,
and made another patch to remove two additional 64GB limit bugs.
This patch J.3 BIOS supports now IDE drives upto 128GB.

I also fixed the UDMA mode bug when using ATA/66 and faster IDE drives.
The BIOS now limits the reported transfer speed to UDMA mode 2 on these faster
drives, the maximum for this chipset.
This allows Win98 to enable DMA mode correctly.

For all other functions, the patched BIOS is identical to the original TTD0616B,
so you don't have to clear the CMOS if you upgrade from this BIOS.

The filename of the patched BIOS is TTD_J3.BIN and you can flash it with
the flash program you normally use to flash a TTD8500 BIOS upgrade.
Please take the usual precautions when flashing your BIOS.

Note that, although this patched BIOS has been tested on a TTD8500 system
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

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Revision history patched Biostar 8500TTD Ver '0616B' BIOS:

09/01/2025 patch J.3
- Fixed the Win98 UDMA mode bug
- Fixed a second 64GB limit bug so the IDE HDD Auto Detection menu selection in
  the BIOS doesn't hang anymore on >64GB drives.

05/10/2012 patch J.2
- fixed the 32GB HDD limit bug for 64GB IDE drive support.
- fixed the first 64GB HDD limit bug for 128GB IDE drive support
- Added detection of the Cyrix MII when set to 4.0x multiplier.

05/07/2012 patch J.1; not released, for testing only
- Added K6-2CXT, K6-III, and K6-2+/K6-III+ support, including Write-Allocation.
- Added 450MHz and 500MHz CPU speed support

