INT 14 - SERIAL I/O - EXTENDED INITIALIZE (CONVERTIBLE,PS)
        AH = 04h
        AL = break status
            00h if break
            01h if no break
        BH = parity
            00h no parity
            01h odd parity
            02h even parity
            03h stick parity odd
            04h stick parity even
        BL = number of stop bits
            00h one stop bit
            01h two stop bits (1.5 if 5 bit word length)
        CH = word length
            00h 5 bits
            01h 6 bits
            02h 7 bits
            03h 8 bits
        CL = bps rate
            00h 110
            01h 150
            02h 300
            03h 600
            04h 1200
            05h 2400
            06h 4800
            07h 9600
            08h 19200
        DX = port number
Return: AX = port status code (see AH=00h)
SeeAlso: AH=1Eh