4. Simple Dialogue -- PDP-10 to 940

   A user at Utah is sitting at a teletype dialed into the University's
   dual PDP-10's.  He wishes to operate the CAL sub-system on the 940 at
   SRI in Menlo Park, California.

    ---------

     ------------                      is issued to call and start
                                       the TELNET subsystem.
   *ESCAPE CHARACTER IS #<CR>          The user indicates an escape
    -------------------------          character which TELNET
                                       will watch for in subsequent
                                       input from the user.

   *CONNECT TO SRI<CR>                 The TELNET subsystem will make
    ------------------                 the appropriate system call
                                       (UUO) to establish a primary
                                       connection.  The connection
                                       will be established, provided:
                                       1.  SRI is willing to accept
                                       another foreign user;
                                       2.  The UTAH user is cleared
                                       for network access at UTAH.
                                       This is determined by a
                                       status word kept in the PDP-10
                                       monitor for each user.

   @LOGIN CARR.                        The user logs in SRI.
    --    -----

   Characters typed on the user's teletype are transmitted unaltered
   through the PDP-10 (user Host) and on to the 940 (serving HOST.)
   (The exception to this is a possible one-for-one code conversion
   required between the UCLA Sigma 7 and the PDP-10, for example).

   @CAL.                               The PDP-10 TELNET subsystem
    -  -                               switches to full duplex,
                                       character-by-character
                                       transmission, since this is
                                       required by 940's.  Characters
                                       typed by the user are
                                       underlined. Full duplex
                                       operation is allowed for by
                                       the PDP-10, though not used
                                       by most DEC subsystems.

   The user wishes to load a CAL file into 940 CAL from the file system
   on his local PDP-10.

   CAL AT YOUR SERVICE
   >READ FILE FROM NETWRK.             'NETWRK' is a predefined
    ----------------------             940 name similar to PAPER
                                       TAPE OR TELETYPE.  The 940
                                       file opening BRS is set to
                                       expect an auxiliary connection
                                       and the file from UTAH.

   #NETWRK: <- DSK:MYFILE.CAL<CR>      The user types the prescribed
    -----------------------------      escape character, followed by
                                       the TELNET command, to send
                                       the desired file to SRI on an
                                       auxiliary connection.  The
                                       user's next statement is in
                                       CAL again.