Older Award BIOSes are missing some features, or contain some bugs, and new versions for older motherboards are not available. I modified BIOSes for 2 motherboards, Gigabyte GA-586HX and GA-586T2. Here is the result:
GA-586HX latest official BIOS ver. 2.9 from Gigabyte
Modified GA-586HX 2.9 BIOS (patch 4)
Enhancements in my modified version:
Test BIOS, sometimes called 3.0 (beta)
Modified GA-586HX 3.0beta (test) BIOS (patch 4)
Enhancements in my modified version:
For additional information and reworks please see Unofficial GA-586HX homepage
For flashing you can use AWDFLASH 5.35a supplied with 2.9 BIOS or AWDFLASH 7.71 that does not show "The program file's part number does not match with your system!" message when changing older and newer BIOSes.
Here you can see detail description of all changes.
GA-586T2 latest official BIOS ver. 2.2 from Gigabyte
Modified GA-586T2 2.2 BIOS (patch 3)
Enhancements in my modified version:
For flashing you can use AWDFLASH 7.71, also already supplied with original 2.2 BIOS.
Here you can see detail description of all changes.
Note that, although these patched BIOS have been tested on different systems without any problems, they are provided "as is" and you use them at your own risk.
Please do not forget to set correct voltage for CPU, for GA-586HX the rework is necessary, for GA-586T2, there iss a DIP switch for selecting the right voltage.