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

1. these structures are allocated by DOS during the scanning of the

CONFIG.SYS file

1. INT 21,67 can be used to allow an application to have more than

20 file handles; the total number of handles is limited still to

  the value of FILES=n in CONFIG.SYS
- the structure of these fields is undocumented;  I do not recommend
  relying on any of this information, instead use it as an aid in
  debugging
- see Bibliography references to Bernd Schemmer and "Data Structures
  Used in IBM PC Compatibles and the PS/2".
- see	INT 21,52