Source : Free On-Line Dictionary of Computing

Ferranti F100-L
     
        An 8-bit processor, with 16-bit addressing, but which could
        only access 32K of memory (1-bit for indirection).  The
        Ferranti F100-L was designed by a British company for the
        British Military.
     
        The unique feature of the F100-L was that it had a complete
        control bus available for a {coprocessor}.  Any instruction
        the F100-L couldn't decode was sent directly to the
        coprocessor for processing.  Applications for coprocessors at
        the time were limited, but the design is still used in modern
        processors, such as the {National Semiconductor} {320xx}
        series.
     
        (1994-11-17)