| Offset | Length | Value | mtools name | Description |
|---|---|---|---|---|
| 00h | 3 | E9 84 01 | jump | Jump to executable code. Only relevant for boot disks |
| 03h | 8 | FLASHPTH | banner | OEM name and version. |
| 0Bh | w 2 | 0200h 512 | secsize | Bytes per sector |
| 0Dh | b 1 | FFh 255 | clsiz | Sectors per cluster (allocation unit size). |
| 0Eh | w 2 | 0001h | nrsvsect | Number of reserved sectors (starting at 0). Make sence as the two first sectors are special. |
| 10h | b 1 | 02h | nfat | Number of FAT's on disk. |
| 11h | w 2 | 0010h | dirents | Number of root directory entries (directory size). |
| 13h | w 2 | 0B40h 2880 | psect | Number of total sectors (0 if partition > 32Mb). |
| 15h | b 1 | F9h | descr | Media descriptor byte. F9h = 3,5 Double Sided, Double High Density diskette (9 sector). |
| 16h | w 2 | 0001h | fatlen | Sectors per FAT. |
| 18h | w 2 | 0012h 18 | nsect | Sectors per track(cylinder). This is 1 Status sector, 1 Control sector and 16 data sectors |
| 1Ah | w 2 | 0001h | nheads | Number of heads. |
| 1Ch | w 2 | 0000h | nhs | Number of hidden sectors. |
| 1Eh | w 2 | Not used | ||
| 20h | dw 4 | 00000000h | bigsect | Number of sectors if offset 13h was 0. |
| 24h | b 1 | 00h | physdrive | Physical drive number. ?? must be inserted by software |
| 25h | b 1 | 00h | reserved | Reserved. |
| 26h | b 1 | 29h | dos4 | Signature byte (29h). |
| 27h | dw 4 | FDFDFDFDh | serial | Volume serial number. |
| 2Bh | 11 | FlashPath.. | label | Volume label. (the two dots in the value are spaces) |
| 36h | 10 | FAT12... | junk | Reserved. ('.' = spaces) |