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