Important: this method creates a Boot-Diskette for DOS. Due to the size limitation of a 1.44MB floppy disk, you can only use a BIOS file and flashtool whose total file size is max ~1.2MB!
Recommendation: i prefer to use the method BIOS Update per bootable USB-Stick!
A bootable pendrive has no size restrictions and more importantly: you can create a BACKUP before updating the BIOS - and that's always a good idea!
The following tools are needed:
rawrite - free Floppy image tool, Download from manufacturer's website
- floppy.img (the boot image file contains the 3 DR-DOS system files command.com, ibmbio.com und ibmdos.com) download  Ultimate BIOS-Boot-Edition - 5.9MB
Flashtool - an executable program (.EXE as file extension), which programs the BIOS file onto the BIOS-Chip, and the BIOS file must be downloaded:
- Mainboard, bought in its original box: from the mainboard manufacturer website, or
- Notebook or brand PC: from the notebook/brand PC manufacturer website.
Both files must be specially designed for the DOS Operation system! If the manufacturer offers only files for Windows, you have to risk the BIOS update either directly under Windows, or you can re-program your old BIOS-Chip, or purchase a new, programmed BIOS-Chip.
Open the Ultimate BIOS-Boot-Edition and the folder boot_floppy_disk english
Copy the boot image file floppy.img to your hard disk.
Start rawrite and choose the menu Write (1.).
Insert the path (2.) to the boot image file floppy.img.
Click the Write-Button (3.) to create the bootable DOS-Diskette.
Rename the filename of your flashtool and the BIOS file, if they have more than 8 characters (not the file extension!).
Copy your flashtool and the BIOS file onto the diskette.
The DOS system files are normally invisible, because their file attribute is set to hidden. If you would like to show these hidden files, you have to enable the option: "Windows-Explorer / Tools / Folder options / View / Show hidden files and folders" and to disable the option "Hide protected operating system files".
Starting the BIOS-Update from Diskette
First, go into your BIOS-Setup and change the Bootsequence to Floppy/Diskette (search for an option like Bootsequence,First Boot Device, or something similarly).
Insert the Diskette and restart your PC. If all went well - DR-DOS starts and you can see the famous DOS-Prompt (A:\>).
Now you can start the BIOS update. Remember: you can only backup your old BIOS onto the Diskette if sufficient space is available! But if your harddisk has a FAT16- or FAT32 partition, it would be a good idea to copy your 2 BIOS files to this partition, and to start the update/backup from your harddisk.