INT 21,4E - Find First Matching File

	AH = 4E
	CX = attribute used during search  (see FILE ATTRIBUTES)
	DS:DX = pointer to ASCIIZ filespec, including wildcards

	on return:
	AX = error code if CF set  (see DOS ERROR CODE)
	DTA = data returned from call in the format:

	Offset Size	 Description

	  00   byte    attribute of search (undocumented)
	       byte    drive letter used in search (DOS 3.1-4.x, undocumented)
	  01   byte    drive letter used in search (undocumented)
	     11bytes   search name used (DOS 3.1-4.x, undocumented)
	  02 11bytes   search name used (undocumented)
	  0C   byte    attribute of search (DOS 3.1-4.x, undocumented)
	  0D   word    directory entry number (0 based, undocumented)
	  0F   word    starting cluster number of current directory; zero
		       for root directory  (DOS 3.2+, undocumented)
	       dword   pointer to DTA (DOS 2.x-3.1, undocumented)
	  11   word    reserved
	  13   word    starting cluster number of current directory; zero
		       for root directory  (DOS 2.x+, undocumented)
	  15   byte    attribute of matching file
	  16   word    file time  (see FILE ATTRIBUTES)
	  18   word    file date  (see FILE ATTRIBUTES)
	  1A   word    file size
	  1E 13bytes   ASCIIZ filename and extension in the form NAME.EXT
		       with blanks stripped

	- returns information on first file matching specifications
	- use INT 21,4F to retrieve following file matches
	- DOS 2.x cannot find . and .. entries, while DOS 3.x can unless
	  they represent the root directory
	- character devices return a zero for size, time and date in DOS 2.x,
	  while DOS 3.0 returns a 40h attribute and current time and date.
	- multiple calls to this function with a character device will
	  result in unpredictable results
	- normal files are always included along with files that match the
	  requested attributes except when the LABEL attribute is requested.
	  DOS 2.x returns all normal files when label is specified but 3.x
	  doesn't.  It's up to the programmer to determine which actually
	  match the requested attributes.
	- bit 8 of CX (file attributes) indicates Novell Netware shareable
	- see	INT 21,1A