INT 7F - Alloy NTNX - SET FILE I/O CHECKING LEVEL
        AH = 26h
        CL = check type to set/reset
            01h directory protection
            02h extended open
            03h flush on every disk write
            04h flush on disk write if any lock set during write
            05h flush on all reads if file written
        AL = new state (00h off, 01h on)
SeeAlso: AH=26h/CL=06h