You are right! Your informations are telling the same to me. So HERE
you can find all the available BIOS'es for your board and you are still using the very first one
is the latest.
Now we need to ensure the latest BIOS is working on your machine so you need to flash from "plain DOS" as it is what you get booting MS-DOS from floppy or USB-Stick or CD-ROM. You can get the howto everywhere on the web.
then you can just use the file from the extracted archive you've downloaded from gigabyte. If you are really sure everything is OK you can just run the batchfile from the DOS-prompt. Don't forget to perform a clear CMOS after the flash is successfully finished. After rebooting you should get to the BIOS settings menu loading the BIOS-defaults and then making your own settings like date and time.
All this should be done with the knowledge of the risk bricking the board!
Good luck and best wishes!