25.1 NS16550

     If you are running FrontDoor under a multi-tasker or in a LAN
     environment, I suggest you replace your 8250 or 16450 UART chip
     with a NS16550AN or NS16550AFN. These are available from several
     electronics outfits for somewhere between USD 17 and USD 23.

     The 16550 family of UARTs have internal buffering (FIFO) and will
     improve performance in multi-tasking and LAN environments. Both
     BNU and X00 has direct support for the 16550 family and can be
     used without modifying your command-line parameters when loading
     them.