Windows:
1.Extract USBFREEDOS.zip
2.Open a command line under usbfreedos folder
3.Run the following command:
#Make sure you have only one USB drive connected (the target usb key)
makebootfat -o usb -E 255 -1 fat12.bss -2 fat16.bss -3 fat32lba.bss -m mbr.bin root
Linux:
1. Download, compile and install makebootfat
wget -O makebootfat-1.4.tar.gz http://downloads.sourceforge.net/project/advancemame/advanceboot/1.4/makebootfat-1.4.tar.gz?r=http%3A%2F%2Fadvancemame.sourceforge.net%2Fboot-download.html&ts=1303229744&use_mirror=voxel
tar -xvzf makebootfat-1.4.tar.gz
cd makebootfat-1.4
./configure
./make
sudo make install
2.Extract USBFREEDOS.zip
3.Open a command line under the usbfreedos folder
4.Run the following command:
#Attention /dev/sdXXX must be changed to point on your usb flash device...
sudo makebootfat -o /dev/sdXXX -E 255 -1 fat12.bss -2 fat16.bss -3 fat32lba.bss -m mbr.bin root
Based on:
Ben’s Bits:
http://bensbits.com/blog/2007/08/21/booting_dos_from_a_usb_flash_drive
Freedos:
http://www.freedos.org/freedos/files/
syslinux:
http://syslinux.zytor.com/wiki/index.php/The_Syslinux_Project
makebootfat:
http://advancemame.sourceforge.net/boot-download.html