INT 67 - LIM EMSsee Expanded Memory Specification 4.0 - ALTERNATE MAP REGISTER SET
	AH = 5Bh
	AL = subfunction
	    00h get alternate map register set
		Return: BL = current active alternate map register set number
			ES:DI -> map register context save area if BL=00h
	    01h set alternate map register set
		BL = new alternate map register set number
		ES:DI -> map register context save area if BL=0
	    02h get alternate map save array size
		Return: DX = array size in bytes
	    03h allocate alternate map register set
		Return: BL = number of map register set; 00h = not supported
	    04h deallocate alternate map register set
		BL = number of alternate map register set
Return: AH = status (00h,80h,81h,84h,8Fh,9Ah-9Dh,A3h,A4h) (see #03656)
Note:	this function is for use by operating systems only, and can be
	  enabled or disabled at any time by the operating system


(Table 03656)
Values for EMSsee Expanded Memory Specification function status:
 00h	successful
 80h	internal error
 81h	hardware malfunction
 84h	undefined function requested
 8Fh	undefined subfunction
 9Ah	specified alternate map register or DMAsee Direct Memory Access register set not supported
 9Bh	all alternate map register or DMAsee Direct Memory Access register sets currently allocated
 9Ch	alternate map register or DMAsee Direct Memory Access register sets not supported
 9Dh	undefined or unallocated alternate map register/DMAsee Direct Memory Access register set
 9Eh	dedicated DMAsee Direct Memory Access channels not supported
 9Fh	specified dedicated DMAsee Direct Memory Access channel not supported
 A3h	source array corrupted
 A4h	operating system denied access
                                                                                

INT 67 - LIM EMSsee Expanded Memory Specification 4.0 - ALTERNATE MAP REGISTER SET - DMAsee Direct Memory Access REGISTERS
	AH = 5Bh
	AL = subfunction
	    05h allocate DMAsee Direct Memory Access register set
		Return: BL = DMAsee Direct Memory Access register set number, 00h if not supported
	    06h enable DMAsee Direct Memory Access on alternate map register set
	       BL = DMAsee Direct Memory Access register set number
	       DL = DMAsee Direct Memory Access channel number
	    07h disable DMAsee Direct Memory Access on alternate map register set
	       BL = DMAsee Direct Memory Access register set number
	    08h deallocate DMAsee Direct Memory Access register set
	       BL = DMAsee Direct Memory Access register set number
Return: AH = status (00h,80h,81h,84h,8Fh,9Ah-9Fh,A3h,A4h) (see #03656)
Note:	this function is for use by operating systems only, and can be
	  enabled or disabled at any time by the operating system