资料来源 : Free On-Line Dictionary of Computing

K56flex
     
         A modem standard developed by {Rockwell} for 56
        {kbps} communications.  K56flex Became more popular than the
        rival {X2} but will be superseded by the official {V.90}
        standard.
     
        [Already superseded?]
     
        (1998-09-08)