INT E0 - DR Multiuser DOS - "A_CONTROL" - GET/SET AUX CONTROL PARAMETERS
	CL = B1h
	DS:DX -> AUX device control block (see #04056)
Return: AX = status
	    0000h successful
		control block updated
	    FFFFh failed
		CX = error code
Note:	also supported by REAL/32
SeeAlso: INT E0/CL=B0h,INT E0/CL=B2h


Format of DR Multiuser DOS AUX device control block:
Offset	Size	Description	(Table 04056)
 00h	BYTE	function (00h get, 01h set)
 01h	BYTE	DTR state (00h low, 01h high, FFh unknown/don't change)
 02h	BYTE	RTS state (00h low, 01h high, FFh unknown/don't change)
 03h	BYTE	DSR state (00h low, 01h high, FFh unknown/don't change)
 04h	BYTE	CTS state (00h low, 01h high, FFh unknown/don't change)
 05h	BYTE	DCD state (00h low, 01h high, FFh unknown/don't change)
 06h	BYTE	RI state (00h inactive, 01h active, FFh unknown/don't change)