INT 7F - Alloy NTNX, MW386 - GET AND CLEAR ACKNOWLEDGE STATUS
        AH = 15h
        CL = 04h
        DX:DI -> status structure (see below)
Return: AL = status
            00h successful
                DX:DI structure filled
            01h busy
            0Ah no acknowledgement has arrived
SeeAlso: AH=14h/CL=01h

Format of status structure:
Offset  Size    Description
 00h    BYTE    sender ID
 01h    BYTE    channel number
 02h  4 BYTEs   receiver status (see AH=12h)