The source is very good documentated (only in English). It supports FAT 12, TSR and a small Multi Kernel System. Floppy Disk Operating System v.1.0 The FDOS Operaing System is 100% written in Assembler (NASM).It provides transparent encryption and decryption of selected devices. Cryptographic disk driver for FreeBSD v.1.1 This is cryptographic disk driver for FreeBSD.