Format of DR Multiuser DOS Disk Parameter Block (DPB): Offset Size Description ) 00h BYTE drive number (00h = A:) 01h BYTE relative unit number 02h WORD sector size in bytes 04h BYTE sectors per cluster - 1 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 number of clusterse on disk 0Fh BYTE number of sectors per FAT 10h WORD sector number of first directory sector 12h 4 BYTEs reserved 16h BYTE media ID byte (see #01356) 17h BYTE 00h if disk accessed, FFh if not 18h 6 BYTEs reserved 1Eh WORD number of free clusters on drive Note: this structure is a subset of the MS-DOS 3.x Drive Parameter Block SeeAlso: #04038,#01357 at INT 21/AH=1Fh,#01395 at INT 21/AH=32h