INT 2F U - NETWORK REDIRECTOR (DOS 3.x only) - UNLOCK REGION OF FILE
AX = 110Bh
BX = file handle
CX:DX = starting offset
SI = high word of size
STACK: WORD low word of size
ES:DI -> SFT for file
SFT DPB field -> DPB of drive containing file
Return: CF set on error
AL = DOS error code (see INT 21/AH=59h)
STACK unchanged
Note:   called by DOS 3.1-3.31 kernel; DOS 4.0+ calls AX=110Ah instead
SeeAlso: INT 21/AH=5Ch

See also: 2F110A

2F110B - NETWORK REDIRECTOR (DOS 3.x only) - UNLOCK REGION OF FILE