INT 21 - DOS 2+ - GET DOS DRIVE PARAMETER BLOCK FOR SPECIFIC DRIVE              
	AH = 32h
	DL = drive number (00h = default, 01h = A:, etc)
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 #01395) for specified
			  drive
	    FFh invalid or network drive
Notes:	the OS/2 compatibility box supports the DOS 3.3 version of this call
	  except for the DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address. at offset 12h
	this call updates the DPBsee Drive Paramter Block by reading the disk; the DPBsee Drive Paramter Block may be accessed
	  via the DOS list of lists (see #01627 at AH=52h) if disk access is not
	  desirable.
	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; only the DOS 4.0+
	  version of the DPBsee Drive Paramter Block has been documented, however
	supported by DR DOS 3.41+; DR DOS 3.41-6.0 return the same data as
	  MS-DOS 3.31
	IBMInternational Busiuness MachinesInternational Busiuness Machines) A hardware, software and other service technology company founded in 1911. ROM-DOS v4.0 also reports invalid/network (AL=FFh) on the ROM(Read-Only Memory) A memory for program storage which may not be changed by the program as it runs. drive
SeeAlso: AH=1Fh,AH=52h,AX=7302h


Format of DOS 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.:
Offset	Size	Description	(Table 01395)
 00h	BYTE	drive number (00h = A:, 01h = B:, etc)
 01h	BYTE	unit number within device driver
 02h	WORD	bytes per sector
 04h	BYTE	highest sector number within a cluster
 05h	BYTE	shift count to convert clusters into sectors
 06h	WORD	number of reserved sectors at beginning of drive
 08h	BYTE	number of FATs
 09h	WORD	number of root directory entries
 0Bh	WORD	number of first sector containing user data
 0Dh	WORD	highest cluster number (number of data clusters + 1)
		16-bit FATsee File Allocation Table if greater than 0FF6h, else 12-bit FATsee File Allocation Table
 0Fh	BYTE	number of sectors per FATsee File Allocation Table
 10h	WORD	sector number of first directory sector
 12h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	address of device driver header (see #01646)
 16h	BYTE	media ID byte (see #01356)
 17h	BYTE	00h if disk accessed, FFh if not
 18h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to next DPBsee Drive Paramter Block
---DOS 2.x---
 1Ch	WORD	cluster containing start of current directory, 0000h=root,
		FFFFh = unknown
 1Eh 64 BYTEs	ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. pathname of current directory for drive
---DOS 3.x---
 1Ch	WORD	cluster at which to start search for free space when writing
 1Eh	WORD	number of free clusters on drive, FFFFh = unknown
---DOS 4.0-6.0---
 0Fh	WORD	number of sectors per FATsee File Allocation Table
 11h	WORD	sector number of first directory sector
 13h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	address of device driver header (see #01646)
 17h	BYTE	media ID byte (see #01356)
 18h	BYTE	00h if disk accessed, FFh if not
 19h	DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address.	pointer to next DPBsee Drive Paramter Block
 1Dh	WORD	cluster at which to start search for free space when writing,
		usually the last cluster allocated
 1Fh	WORD	number of free clusters on drive, FFFFh = unknown
SeeAlso: #01357,#01663,#01787 at AX=7302h,#04039 at INT E0/CL=71h