| Offset | Size | Description |
|---|---|---|
| 00 | dword | pointer to next system file table; offset of ffffh indicates last table in chain |
| 04 | word | number of file descriptors in table |
| 06 | nbytes | file descriptor table of the format (40 bytes each): |
| Offset | Size | Description |
|---|---|---|
| 00 | byte | count of handles referring to this file or zero if file is no longer open |
| 01 | byte | open mode |
| 02 | byte | file attribute |
| 03 | byte | drive (1=A, 2=B:, …, 0=char device) |
| 04 | 11bytes | filename in FCB format |
| 0F | word | unknown |
| 11 | word | unknown |
| 13 | dword | file size |
| 17 | word | file date |
| 19 | word | file time |
| 1B | byte | device attribute |
| 1C | word | starting cluster of file (block device) |
| dword | pointer to device driver (if char device) | |
| 1E | word | if block device, relative cluster within file of the last cluster read; zero if file has never been read or written |
| 20 | word | absolute cluster number of current cluster |
| 22 | word | unknown |
| 24 | dword | current file position |
| Offset | Size | Description |
|---|---|---|
| 00 | dword | pointer to next system file table; offset of ffffh indicates last table in chain |
| 04 | word | number of file descriptors in table |
| 06 | nbytes | file descriptor table of the format (53 bytes each): |
| Offset | Size | Description |
|---|---|---|
| 00 | word | count of handles referring to this file or zero if file is no longer open |
| 02 | word | open mode, bit 15 set if file id opened via FCB |
| 04 | byte | file attribute |
| 05 | word | device info word |
| 07 | dword | if char device pointer to device driver header if block device pointer to DOS Device Control Block |
| 0B | word | starting cluster of file |
| 0D | word | file time |
| 0F | word | file date |
| 11 | dword | file size |
| 15 | dword | current file position |
| 19 | word | if block device, relative cluster within file of the last cluster read |
| 1B | word | absolute cluster number of last cluster read zero if file has never been read or written |
| 1D | word | sector number containing the directory entry |
| 1F | byte | number of dir entry within sector |
| 20 | 11bytes | filename in FCB format |
| 2B | dword | SHARE pointer to previous SFT sharing same file |
| 2F | word | SHARE number of network machine opening file |
| 31 | word | PSP segment of file owner |
| 33 | word | offset within SHARE code segment of sharing record 0000h = none |
| Offset | Size | Description |
|---|---|---|
| 00 | dword | pointer to next system file table; offset of ffffh indicates last table in chain |
| 04 | word | number of file descriptors in table |
| 06 | nbytes | file descriptor table of the format (59 bytes each): |
| Offset | Size | Description |
|---|---|---|
| 00 | word | count of handles referring to this file or zero if file is no longer open |
| 02 | word | open mode, bit 15 set if file id opened via FCB |
| 04 | byte | file attribute |
| 05 | word | device info word |
| 07 | dword | if char device pointer to device driver header if block device pointer to DOS Device Control Block or REDIR data |
| 0B | word | starting cluster of file |
| 0D | word | file time |
| 0F | word | file date |
| 11 | dword | file size |
| 15 | dword | current file position |
| 19 | dword | if network redirector, pointer to REDIRIFS record word if local block dev, relative cluster within file of the last cluster read |
| 1B | dword | if local, sector number of directory entry |
| 1F | byte | if local, number of directory entry within sector |
| 20 | 11bytes | filename in FCB format |
| 2B | dword | SHARE pointer to previous SFT sharing same file |
| 2F | word | SHARE number of network machine opening file |
| 31 | word | PSP segment of file owner |
| 33 | word | offset within SHARE code seg of sharing record 0000h = none |
| 35 | word | absolute cluster number of last cluster read zero if file has never been read or written |
| 37 | dword | pointer to file IFS driver, NULL if native DOS |
