Source : Free On-Line Dictionary of Computing

as31
     
         An {8031}/{8051} {assembler} by Ken
        Stauffer  and Theo Deraadt which
        produces a variety of {object code} output formats.  The
        distribution includes an {assembler}, {yacc} {parser}, and
        documentation.  as31 runs on {Sun-3}, {Sun-4}, {SunOS 4.0},
        {Tandy 6000}, and {Xenix}.
     
        Current version: 1, as of 1990-01-26.
     
        {as31 Home (http://www.pjrc.com/tech/8051/#as31_assembler)}.
     
        (2002-05-07)