INT 14,4 - Serial Port Extended Initialization (PS/2 & later systems)
AH = 04 AL = break setting BH = parity setting BL = stop bit setting CH = word length setting CL = baud rate setting DX = zero based serial port number (0-3) --- Break Setting --- 1 = break 0 = no break ----- Parity Setting ----- --- Stop Bit Setting --- 0 = no parity 0 = one stop bit 1 = odd parity 1 = 2 stop bits 2 = even parity 1½ if register CH=0 3 = stick parity odd (5 bit word length) 4 = stick parity even -- Word Length Setting -- ---- Baud rate Setting ---- 0 = 5 bits 0 = 110 5 = 2400 1 = 6 bits 1 = 150 6 = 4800 2 = 7 bits 2 = 300 7 = 9600 3 = 8 bits 3 = 600 8 = 19200 4 = 1200 on return: AH = port status AL = modem status - for status bits see INT 14,STATUS