Int 21/AX=440Dh/CX=084Bh

MS-DOS 7.0+ - GENERIC IOCTL - LOCK PHYSICAL VOLUME

AX = 440Dh
CX = 084Bh / 484Bh
(category code 08h for FAT12/16, 48h for FAT32; minor code 4Bh)
BH = logical drive number (00h = default, 01h = A:, etc.)
BL = lock level (00h-03h)
DX = drive permissions (see #01575) for Level 1 lock or second
Level 0 lock when formatting

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

Note: The physical volume must be locked before direct disk writes via INT 13 are permitted by Windows95

See Also: AX=440Dh/CX=086Ch

Category: DOS Kernel - Int 21h - M

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