Format of FindFirst data block:
Offset	Size	Description	)
---PC-DOS 3.10, PC-DOS 4.01, MS-DOS 3.2/3.3/5.0---
 00h	BYTE	drive letter (bits 0-6), remote if bit 7 set
 01h 11 BYTEs	search template
 0Ch	BYTE	search attributes
---DOS 2.x (and some DOS 3.x???)---
 00h	BYTE	search attributes
 01h	BYTE	drive letter
 02h 11 BYTEs	search template
---WILDUNIX.COM---
 00h 12 BYTEs	15-character wildcard search pattern and drive letter (packed)
 0Ch	BYTE	search attributes
---DOS 2.x and most 3.x---
 0Dh	WORD	entry count within directory
 0Fh	DWORD	pointer to DTA???
 13h	WORD	cluster number of start of parent directory
---PC-DOS 4.01, MS-DOS 3.2/3.3/5.0---
 0Dh	WORD	entry count within directory
 0Fh	WORD	cluster number of start of parent directory
 11h  4 BYTEs	reserved
---OS/2 MVDM---
 00h	WORD	"OS2_BMP_handle"
 02h	WORD	"OS2_LastEnt"
 04h	DWORD	"OS2_Checksum"
 08h	BYTE	"OS2_usi_flag"
 09h	DWORD	used by DOS emulator for second pass for volume-label searches
 0Dh	WORD	(ret) "DOS_LastEnt" entry count within directory
 0Fh	BYTE	OS/2 Processed-FindFirst flag
		00h FindFirst processed by DOS
		42h FindFirst processed by OS/2
 10h  5 BYTEs	reserved for future use
---all versions, documented fields---
 15h	BYTE	attribute of file found
 16h	WORD	file time (see #01665 at AX=5700h)
 18h	WORD	file date (see #01666 at AX=5700h)
 1Ah	DWORD	file size
 1Eh 13 BYTEs	ASCIZ filename+extension