Directory Entries
Offset Length (LENGT) Description (Format) 00h 8 byte (8 Bytes) file name (Filename) ASCII code, but if the first byte is the following code is Conditional code: (ASCII Chars, or Special Code if first char :) 00h = Name Name Never used) 05H = The first byte is E5H (First Character or Name Is Realy E5H) E5H = file is used But has been deleted.
(File WAS Used, But Has Been ERASED) 2EH = Login is a directory (entry is a directory) must be added with a space FIELD 08H 3 byte (3bytes) extension [FILE TYPE (Extension)] ASCII Code Character (ASCII Chars) must be added with space Field 0BH 1 byte (BYTTRIBUTE): Bit Codes: Bit0 = only Read-only bit1 = hidden (hidden) bit2 = system (SYSTEM) Bit3 = Volumn Label Bit4 = Directory Bit5 = Archive (Archive) Bit6 = Alternate (unused) bit7 = Alternate (unused) 0ch 10 byte (10 Bytes) Reserved Time File Last Updated Code Signature: (No Symbol 16 Enciprived Integers) Time = Hours * 2048 Minute * 32 Second 2 [coded word: (unsigned 16 bit-bit integer) time = hr * 2048 min * 32 sec 2] must first be meaningful bytes (*: Least Significant Byte First) 18H Word (Word) final Date File Last Updated Code Significance: (No Symbol 16 Enciprived Integer) Time = (Year-1980) * 512 Month * 32 Day [Coded Word: (unsigned 16 bit-bit integer) Time = (YR-1980) * 512 MON * 32 day] First, you must be a meaningful byte (*: Least Significant Byte First) 1AH Word (Word) Start Cluster Single-word Binary Integer (Word Binary Integer *) 1CH Double Word (DBL Word) File Size (Double Word Binary INTE) GER *) File Property (File Attribute Byte)
76543210 indicates when its value is "1" indicates when its value is "0", the read-only file can be read-only file (READ / Write File) V Hidden File (Visible File) V. Regular File Volume (Volumn Name) Normal File (Directory Name) Regular file v files After the last backup, there is no change in the last backup of the file (FILE Unchange Since Last Backup) is best to combine the DOS command Attrib.
FAT16 Structure (FAT16 Structure):
Entry Example (Example Value) Used (USE) 0 FFF8 Hard Disk Number Bytode (CLUSTER VALUE): 0000 = Unused Cluster 0002-FFFF = NEXT Cluster Number) FFF0-FFF6 = Reserved Cluster FFF7 = Bad Cluster Marker (Cluster Marked Bad) FFF8-FFFF = Fair Cluster Last Cluster in file 3 0004 4 0005 5 FFFFF 6 0000
Disk boot recording structure (boot record layout)
DOS3.3 and DOS4.0 disk boot recording structure (Boot Record Layout)
Offset Length Description (DOS Version) 003 byte (3 bytes) JMP to Boot Code 038 byte (8 BYTES) OEM Name and Version (Oem Name and Version) 0B1 Word (bytes per sector) 0D1 bytes (Byte) All clusters The number of sectors containing Sector Sectors Per Cluster (Must Be a Power Of 2) 0e1 Word (Word) Reserved Sector [RESERVED SECTORS (for Dir, FAT, etc.)] 101 byte (BYTE) File Allocation Table Number Of Copies Of Fat 111 Word Root Directory Directory (Maximum Number) Of root directory entries 131 Words (Total Number of Sectors in Logical Image) 151 bytes (Byte) Media Description byte (Byte) Document Assignment NUMBER OF SECTORS IN FAT 181 Word (Word) Number of Sectors Per TRACK 1A1 Number of Sectors Per TRACK 1A1 Number Of Heads 1C1 Word (Word) Hide Seaf NUMBER OF Hidden Sectors 1E1 Word hidden Digital (DBL Word) Digital (Number Of Logical Sectors) DOS5.0 Disk Boot Record Structure Boot sector structru
Offset length (LENGTH) Description (DOS Version) 1E Double Word (DBL Word) DOS 5.0 Boot Sector Structure (Boot Sector Structure)
