UMBC CMSC 211 |
Offset | Size | Description |
---|---|---|
00h | 1 | Drive number (0=A:,1=B:,etc) |
01h | 1 | unit number within device driver |
02h | 2 | bytes per sector |
04h | 1 | highest sector number within cluster |
05h | 1 | shift count to convert clusters into sectors |
06h | 2 | number of reserved sectors at beginning of drive |
08h | 1 | number of FATs |
09h | 2 | number of root directory entries |
0Bh | 2 | number of first sector containing user data |
0Dh | 2 | highest cluster number (number of clusters + 1) |
0Fh | 2 | number of sectors per FAT |
11h | 2 | sector number of first directory sector |
13h | 2 | address of device driver header |
17h | 1 | media ID byte |
18h | 1 | 00h if disk is accessed, FF if not |
19h | 4 | pointer to next DPB |
1Dh | 2 | cluster at which to start search for free space when writing |
1Fh | 2 | number of free clusters on drive, FFFFh = not known |