INT 21 - MS-DOS 7.0+ - GENERIC IOCTL - UNLOCK PHYSICAL VOLUME AX = 440Dh CX = 086Bh / 486Bh (category code 08h for FAT12/16, 48h for FAT32; minor code 6Bh) BH = logical drive number (00h = default, 01h = A:, etc.) Return: CF set on error AX = error code (01h,02h,etc.) (see #01680 at AH=59h/BX=0000h) CF clear if successful Desc: lock all logical volumes on the same physical volume as the indicated drive SeeAlso: AX=440Dh"DOS 3.2+",AX=440Dh/CX=084Bh,AX=440Dh/CX=086Ah