INT 21 - DOS 1+ - GET DRIVE PARAMETER BLOCK FOR DEFAULT DRIVE                   
	AH = 1Fh
Return: AL = status
	    00h successful
		DS:BX -> Drive Parameter BlockThe DOS Drive Parameter Block stores the description of the media layout for a logical drive, as well as some housekeeping information.  See also INT 21h Function 1Fh and INT 21h Function 32h. (DPBsee Drive Paramter Block) (see #01357 for DOS 1.x,
			AH=32h for DOS 2+)
	    FFh invalid drive
Note:	this call was undocumentedInformation about a product which is not publicly available from the manufacturer, and must be determined by reverse-engineering (disassembly, trial-and-error, etc.).	 Undocumented information tends to change -- often dramatically -- between successive revisions of a product, since the manufacturer has no obligation to maintain compatibility in behavior which is not explicitly stated. prior to the release of DOS 5.0; however,
	  only the DOS 4.0+ version of the DPBsee Drive Paramter Block has been documented
SeeAlso: AH=32h,AX=7302h


Format of DOS 1.1 and MS-DOS 1.25 drive parameter block:
Offset	Size	Description	(Table 01357)
 00h	BYTE	sequential device ID
 01h	BYTE	logical drive number (0=A:)
 02h	WORD	bytes per sector
 04h	BYTE	highest sector number within a cluster
 05h	BYTE	shift count to convert clusters into sectors
 06h	WORD	starting sector number of first FATsee File Allocation Table
 08h	BYTE	number of copies of FATsee File Allocation Table
 09h	WORD	number of directory entries
 0Bh	WORD	number of first data sector
 0Dh	WORD	highest cluster number (number of data clusters + 1)
 0Fh	BYTE	sectors per FATsee File Allocation Table
 10h	WORD	starting sector of directory
 12h	WORD	address of allocation table
Note:	the DOS 1.0 table is the same except that the first and last fields
	  are missing; see INT 21/AH=32h for the DOS 2+ version
SeeAlso: #01395,#04039