C56(9.1)                                                 C56(9.1)

          c56 - terminal program with data compression


          C56 replaces the program in the layer on its standard output
          with an emulator for a Teletype DMD 5620 stand-alone termi-
          nal.  In the resulting layer, environment variable TERM is
          set appropriately.  The character stream from the host to
          the terminal is compressed using an adaptive algorithm that
          often doubles the effective data rate of a slow host-
          terminal connection.

          This terminal program is most useful at speeds of 2400 baud
          and below.  At 9600 baud, the terminal cannot generate char-
          acters and put them on the screen fast enough to keep up,
          and the extra overhead introduced by decompression just
          slows things down.

          Unexported shell parameters and functions are lost.
          Race conditions occasionally leave the tty modes set improp-
          erly at start-up.