INT 66 - MIDPAK - REGISTER XMIDI                                                
	AX = 0704h
	CX:BX -> XMIDI sequence data
	DI:SI = length of XMIDI data
Return: AX = status
	    0000h unable to register XMIDI data
	    0001h XMIDI file registered resident
	    0002h XMIDI file was registered to the application