Int 2F Fn 4A15  - Ms Emm386.exe V4.46+ - Install I/o Virtualization Handl  [-]

   AX = 4A15h
   BX = 0000h (function number)
   DX = starting I/O address
   EDX high word = ending I/O address
   CX = number of ports to trap
   DS:SI -> I/O dispatch table (see #2501)
   DI = size of client's code and data

Return: CF clear if successful
   CF set on error

Notes: this interface is only available in virtual-86 mode; the I/O handlers
     will be called in protected mode
   only ports 0100h-FFFFh may be trapped; EMM386 reserved ports 0000h-
     00FFh

Format of EMM386 I/O dispatch table [array]:
Offset Size    Description (Table 2501)
 00h   WORD    I/O port offset (added to DX to get actual port number)
 02h   WORD    offset of I/O handler for port (see #2502)

(Table 2502)
Values EMM386 I/O dispatch function is called with:
   CX = Ring0 code selector for I/O handler's segment
   DS = Ring0 data selector for I/O handler's segment (alias of CS)
   EDX = faulting I/O address
   ECX = direction (00000008h for byte output, 00000000h for byte input)
   EAX = data in/out

Return: (via FAR RET)
   CF clear if I/O access successfully virtualized
   CF set if access not virtualized (default handler will be called to
         perform the I/O)

See Also: #2501