INT 7F - Alloy 386/MultiWare (MW386), Novell-Type Network Executive (NTNX)
Notes:  the words at C800h:0000h and C800h:0002h will both be 584Eh if the
          MW386 multitasking system is present (i.e. signature "NXNX")
        NTNX allows its API to be placed on a different interrupt than 7Fh at
          load time.  To determine the actual vector used, open the device
          "SPOOLER" with INT 21/AX=3D02h, place it in RAW mode with
          INT 21/AX=4400h and INT 21/AX=4401h, then read one byte which will
          be the actual interrupt number being used; the other interrupts may
          be found with INT 7F/AH=09h/CL=03h