Int 67 Fn 5DEB  - Rm386 - V86-mode I/o Trapping Port Control               [m]

   AX = 5DEBh
   BX = function
       00h disable V86-mode trapping for specified port
       01h enable V86-mode trapping for specified port
       02h get V86-mode trapping state for specified port
   DX = port for which to enable/disable/query trapping

Return: AH = status
       00h successful
       BX = current trapping state (00h off, 01h on) (function 02)
       A7h invalid port ID
       A8h reserved port--cannot trap/untrap (DMA/INT/KBD controllers)

Notes: RM386 traps this functions on the initial transition to protected
     mode caused by the INT instruction, which means it can not be
     overridden simply by hooking the interrupt

See Also: AX=5DEAh