INT 94 u - Media Vision PCM.COM - CHECK BOARD ADDRESS                           
	SI = 8002h
Return: AX = status
	    0000h if board not at specified I/O address
	    other if board found
Note:	the I/O address is specified by ORing the base I/O port shifted left
	  four bits into SI before calling INT 94
SeeAlso: SI=8000h