INT E0 - DR Multiuser DOS - "A_CONFIG" - GET/SET AUX DEVICE PARAMETERS
        CL = B0h
        DX:DX -> AUX device parameter block (see below)
Return: AX = status
            0000h successful
                parameter block updated
            FFFFh failed
                CX = error code
SeeAlso: INT E0/CL=A5h,INT E0/CL=B1h

Format of AUX device parameter block:
Offset  Size    Description
 00h    BYTE    function (00h get, 01h set)
 01h    BYTE    baud rate (see below) FFh = don't change/unknown
 02h    BYTE    parity
                00h none
                01h odd
                02h none
                03h even
                04h stick parity bit
                FFh don't change/unknown
 03h    BYTE    stop bits (00h one, 01h 1.5, 02h two, FFh unknown/don't change)
 04h    BYTE    data bits (05h-08h or FFh unknown/don't change)
 05h    BYTE    handshake (00h none, 01h DTS/DSR, 02h RTS/CTS, 04h XON/XOFF,
                FFh unknown/don't change)
 06h    BYTE    XON character, FFh unknown/don't change
 07h    BYTE    XOFF character, FFh unknown/don't change

Values for baud rate:
 00h = 50 baud
 01h = 62.5 baud
 02h = 75 baud
 03h = 110 baud
 04h = 134.5 baud
 05h = 150 baud
 06h = 200 baud
 07h = 300 baud
 08h = 600 baud
 09h = 1200 baud
 0Ah = 1800 baud
 0Bh = 2000 baud
 0Ch = 2400 baud
 0Dh = 3600 baud
 0Eh = 4800 baud
 0Fh = 7200 baud
 10h = 9600 baud
 11h = 19200 baud
 12h = 38400 baud
 13h = 56000 baud
 14h = 76800 baud
 15h = 115200 baud