Four or eight RS-232, RS-422 and/or RS-485 serial ports can be provided on a single PC/104 board by the Emerald-MM line of serial-port PC/104 modules. Single- or multi-protocol versions are available. The increased number of ports enables designers to pack more features into a smaller space.All protocol configuration is done port-by-port with jumpers so that designers can select configurations easily without changing chips on the board. The quad version is also available with a J1708-compatible interface for automotive applications. Data rates are 115 kbps standard and 460.8 kbps optional. The boards’ flexible address and interrupt selection minimizes the problem of placing strain on system interrupt and I/O address resources.