以下资料仅供参考:
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目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
目录项(Directory Entries)
| offset | length | description | format | comments |
| 00H | 8 bytes | filename | ASCII chars,or special code if first char: 00H=name never used 05H=first character or name is realy E5H E5H=file was used,but has been erased 2EH=entry is a directory | must be padded with spaces to fill field |
| 08H | 3 bytes | file type(extension) | ASCII chars | must be padded with spaces to fill field |
| 0BH | byte | file attribute | bit codes: bit0=read-only bit1=hidden bit2=system bit3=volumn label bit4=directory bit5=archive bit6=unused bit7=unused | |
| 0CH | 10 bytes | reserved | ||
| 16H | word | time file last updated | coded word:(unsigned 16 bit-bit integer) time=Hr*2048+Min*32+Sec+2 | *:least significant byte first |
| 18H | word | date file last updated | coded word:(unsigned 16 bit-bit integer) time=(Yr-1980)*512+Mon*32+Day | *:least significant byte first |
| 1AH | word | starting cluster number | word binary integer* | |
| 1CH | dbl word | file size | double word binary integer* |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
文件属性字节(File attribute byte)
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | meaning if set to 1 | meaning if set to 0 |
| v | read-only file | read/write file | |||||||
| v | hidden file | visible file | |||||||
| v | system file | regular file | |||||||
| v | volumn name | regular file | |||||||
| v | directory name | regular file | |||||||
| v | file changed since last backup | file unchanged since last backup | |||||||
| v | v | reserved | reserved |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
FAT16结构(FAT16 structure):
| Entry | Example Value | Use |
| 0 | FFF8 | Disk ID byte |
| 1 | FFFF | Filler |
| 2 | 0003 | Cluster value: 0000 = unused cluster 0002-ffff= next cluster number fff0-fff6= reserved cluster fff7 = cluster marked bad fff8-ffff= last cluster in file |
| 3 | 0004 | |
| 4 | 0005 | |
| 5 | FFFF | |
| 6 | 0000 |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
磁盘引导记录结构(BOOT record layout)
dos3.3 and dos4.0 BOOT record layout
| offset | length | description | DOS version |
| 00 | 3 bytes | JMP to boot code | |
| 03 | 8 bytes | OEM name and version | |
| 0B | word | bytes per sector | |
| 0D | byte | sectors per cluster(must be a power of 2) | |
| 0E | word | reserved sectors(for Dir,FAT,etc.) | |
| 10 | byte | Number of copies of FAT | |
| 11 | word | Maximum number of root directory entries | |
| 13 | word | Total number of sectors in logical image | |
| 15 | byte | Media descriptor byte | |
| 16 | word | number of sectors in FAT | |
| 18 | word | number of sectors per track | |
| 1A | word | number of heads | |
| 1C | word | number of hidden sectors | |
| 1E | word | HO number of hidden sectors | |
| 20 | dbl word | number of logical sectors |
DOS5.0 BOOT sector structrure
| offset | length | description | DOS version |
| 1E | dbl word | number of hidden sectors | DOS 5.0 boot sector structure |
| 22 | dbl word | number of sectors if the size of the drive is larger than 32MB | |
| 23 | byte | drive number used Internally by DOS | |
| 24 | byte | reserved | |
| 25 | byte | boot signature. always 29H. | |
| 29 | dbl word | volumn ID number | |
| 34 | 11 bytes | Volumn label | |
| 3C | 8 bytes | file-system type |
目录项(Directory Entries)
文件属性字节(File attribute byte)
FAT16结构(FAT16 structure)
磁盘引导记录结构(BOOT record layout)
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