如何使用BIOS下的USB闪存驱动器执行低级IO（与软盘相比）？

I have recently been studying some bootstrap code which was intended for use with a floppy drive. My goal is to modify the program so that it uses my USB flash drive. Now I see how the INT 13H function has been used with the floppy device, but I guess my question is, how will communicating with the USB drive differ?I have recently been studying some bootstrap co