| Offset |
Size |
Description |
|
00h
|
WORD
|
number of file handles referring to this file |
|
02h
|
WORD
|
file open mode (see AX=6C00h, #01402
at AH=3Dh)
bit 15 set if this file opened via FCB |
|
04h
|
BYTE
|
file attribute (see #01420
at AX=4301h) |
|
05h
|
WORD
|
device info word (see #01423
at AX=4400h)
| bit 15 |
: |
set if remote file |
| bit 14 |
: |
set means do not set file date/time on closing |
| bit 12 |
: |
set means don't inherit on EXEC |
| bits 5-0 |
: |
drive number for disk files |
|
|
07h
|
DWORD
|
pointer to device driver header if character device
else pointer to DOS Drive Parameter Block (see #01395
at AH=32h) |
|
0Bh
|
WORD
|
starting cluster of file |
|
0Dh
|
WORD
|
file time in packed format (see #01665
at AX=5700h)
not used for character devices in DR DOS |
|
0Fh
|
WORD
|
file date in packed format (see #01666
at AX=5700h)
not used for character devices in DR DOS |
|
11h
|
DWORD
|
file size |
|
---system file table---
|
|
15h
|
DWORD
|
current offset in file (may be larger than size of file; INT
21/AH=42h does not check new position) |
|
---FCB table---
|
|
15h
|
WORD
|
counter for last I/O to FCB |
|
17h
|
WORD
|
counter for last open of FCB (these are separate to determine
the times of the latest I/O and open) |
|
---
|
|
19h
|
WORD
|
relative cluster within file of last cluster accessed |
|
1Bh
|
WORD
|
absolute cluster number of last cluster accessed
0000h if file never read or written??? |
|
1Dh
|
WORD
|
number of sector containing directory entry (see #01352) |
|
1Fh
|
WORD
|
byte offset of directory entry within sector |
|
21h
|
11 BYTEs
|
filename in FCB format (no path/period, blank-padded) |
|
2Ch
|
DWORD
|
(SHARE.EXE) pointer to previous SFT sharing same file |
|
30h
|
WORD
|
(SHARE.EXE) network machine number which opened file
(Windows Enhanced mode DOSMGR uses the virtual machine ID as the machine
number; see INT 2F/AX=1683h) |
|
32h
|
WORD
|
PSP segment of file's owner (first three entries for
AUX/CON/PRN contain segment of IO.SYS startup code) |
|
34h
|
WORD
|
(SHARE.EXE) offset in SHARE code seg of share record |
|
36h
|
WORD
|
??? apparently always 0000h |