INT 2F - MS EMM386.EXE v4.46+ - INSTALL I/O VIRTUALIZATION HANDLER              
	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 #02815)
	DI = size of client's code and data (size of DS segment which must be
	      made available to I/O dispatch function in protected mode)
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 02815)
 00h	WORD	I/O port number
 02h	WORD	offset of I/O handler for port (see #02816)


(Table 02816)
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)
		(reportedly 00h for byte/word input, 04h for byte/word output
		  under DOS 6.22 EMM386)
	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)
BUG:	32-bit I/O on trapped ports hangs the DOS 6.22 EMM386
SeeAlso: #02815