USB 

Most of today's laptop computers have no RS232 port and only support USB.  A USB interface is available for all Brookhouse NMEA multiplexers as a reasonably priced optional extra. The integral USB adapter allows direct connection of the NMEA Multiplexer to a USB 1.1 or 2.0 compliant port. Brookhouse multiplexers with the USB interface can still be connected via a serial RS232 port as well. A USB cable of 1.8m (6 ft) length is included as well as USB driver software for all Windows versions and Mac.