http://students.cs.byu.edu/~cs345ta/labs/summer03_specs/lab_fat_help.htm
http://www.ncc.up.pt/~rslopes/aulas/0304/SO/trab3.html
http://students.cs.byu.edu/~cs345ta/labs/winter04_specs/lab_fat2.htm
http://freedos-32.sourceforge.net/fat.html