rfc76.txt

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   routines.  The system will keep tables in core and on the small disk
   for logging peripheral usage, keeping track of connections on the
   network, queuing up of tasks that cannot be immediately performed,
   storing attributes of remote hosts, etc.

   Since network hosts handle communications in character-at-a-time or
   message modes, and may or may not echo characters over the network,
   the system takes this into account when handling connections to
   specific hosts.  If the connection is in message mode, minimal line-
   by-line editing facility (character and line deletion) is provided.

   A means for the user to change flag and message transmit characters
   is provided to prevent incompatibilities which may arise between the
   PDP-11 and other hosts.

   This document does not describe control card syntax for card reader
   usage, nor does it describe the operator's control language.  These
   will be described in later documents.

Character Set

   <character> ::= <letter> | <digit> | <special> | <space>

   <letter>    ::= A | B | ... | Y | Z



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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


   <digit>     ::= 0 | 1 | ... | 8 | 9

   <special>   ::= ! | " | # | $ | % | & | ' | ( | ) | * | + | , | - |
                   . | / | : | : | < | = | > | ? | @ | [ |  | ] | ^ |
                     |` | { | <bar> | }

Identifiers

   <identifiers> ::= <letter> | <identifier> <letter> |
                     <identifier> <digit>

        Semantics:  Identifiers are used to designate peripheral units,
        host computers, etc.  No identifier may exceed 8 characters in
        length.

Numbers

   <integer> ::= <digit> | <integer> <digit>

        Semantics:  <integer> are the only form of number allowed in the
        control language.  They must not exceed 2^15-1.

Peripheral Designator

   <peripheral designator> ::= <device class> <device number> | OPR

   <device number>         ::= <digit> | <digit> <digit> |

   <device class>          ::= CR | CP | LP | DT | TR | SS

        Semantics:  Peripheral designators name specific peripheral
        devices.  Device lasses designate classes of peripherals.

        OPR designates the operator's console teletype.  The classes of
        peripherals corresponding to the device classes are given on the
        following table:

            <device class>                      type of peripheral

                CR                                  card reader
                CP                                  card punch
                LP                                  line printer
                DT                                  DECtape
                TR                                  terminal
                SS                                  storage scope






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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


File Label

   <file label>     ::=  <tape label> |  <tape label> / <tape file name>

   <tape label>     ::=  <identifier>

   <tape file name> ::=  <identifier>

        Semantics: File labels provide the means for designating tape
        files symbolically.  If the <tape label> form is used, the
        designated file is assumed to occupy the entire tape.

Flagged Control Statement

   <flagged control statement>  ::= <flag> <control statement>

   <flag>                       ::= <special>

        Semantics: <Flagged control statement>s arc the user's names of
        communicating with the PDP-11 system.  The <flag> must be the
        system default flag (!) or a substitute which the user provides
        by means of the <flag statement>.  Input to the system which
        does not begin with a <flag> will be passed on to the process to
        which the user is connected, if any.

Control Statements

   <control statement>  ::= <link statement> |

                            <copy statement> |

                            <end statement> |

                            <user statement> |

                            <status statement> |

                            <out statement> |

                            <to statement> |

                            <escape statement> |

                            <back statement> |

                            <delete statement> |

                            <transmit statement> |



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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


                            <lock statement> |

                            <unlock statement> |

                            <assign statement> |

                            <label statement> |

                            <create statement> |

Link Statement

   <link statement> ::= LINK TO <host> <q>

   <q>              ::= <empty> |

                        QUEUE   |

                        QUEUE    <integer>

        Semantics: The Link statement directs the system to set up a
        connection between the user's unit and a remote host.  The <q>
        construct allows the user to specify that, if the connection
        cannot be set up immediately, the system is to keep trying.  If
        the QUEUE form is used, the system will keep trying
        indefinitely.  If the QUEUE integer form is used, the system
        will try for integer minutes.

Copy Statement

   <copy statement>   ::= COPY <source> TO <dest> <q>

   <source>           ::= NETWORK |

                          <file label> |

                          <source class> |

                          <source device>

   <source class>     ::= CR | TR | SS |

   <source device>    ::= <source class> <device number>

   <dest>             ::= NETWORK

                          <file label> |




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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


                          <dest class> |

                          <dest device>

   <dest class>       ::= CP | LP | TR | SS

   <dest device>      ::= <dest class> <device number>

        Semantics: The <copy statement> directs the system to set up a
        connection between the <source> and <dest> and copy records of
        information between them.  If the <device class> or <device>
        form is used for either <source> or <dest>, the copy process
        cannot begin until a unit is assigned to the user.  If the <file
        label> form is used, the copy process can likewise not proceed
        until the system has access to a properly labeled tape. if the
        NETWORK form is used, a connection to a remote process must be
        pending.

        The <q> construct has the same meaning as for the <link
        statement>, with the additional provision that the condition
        that caused the process to be incomplete may be the lack of a
        device assignment.

End Statement

   <end statement>   ::= END

        Semantics: The <end statement> causes the current connection to
        be terminated.

User Statement

   <user statement>  ::= USER = <identifier>

        Semantics: The <user statement> is used during the log in
        process to allow the user to identify himself.

Status Statement

   <status statement> ::= STATUS <device class> |

                          STATUS <peripheral designator>

        Semantics: The <status statement> allows the user to interrogate
        the system as to the status of a device or class of devices.






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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


Out Statement

   <out statement> ::= OUT|LEAVE

        Semantics: The <out statement> allows a user to log out of the
        system.  If the OUT form is used, all queued process initiated
        by the user are terminated.  The LEAVE from does not terminate
        such pending queued processes so long as these processes do not
        directly involve the user's terminal.

To Statement

   <to statement> ::= TO CON :<text> |  TO <user> : <text>

        Semantics: The <to statement> allows the user to send a message
        to the operator or another logged-in user.

Flag Statement

   <flag statement> ::= FLAG = <special>

        Semantics: The <flag statement> allows the user to define the
        character which the system recognizes as preceding a control
        statement as distinguished from a message to a remote process to
        which he may be attached.  The default flag character is "|".

Back Statement

   <back statement> ::= BACK ? {ascii special or control character}

        Semantics: The <back statement> allows the user to define the
        character which, in control or message mode, causes the system
        to "forget" the previous input character.  The default backspace
        character is RUBOUT (ASCII 1778).

Delete Statement

   <delete statement> ::= DELETE = {ASCII special or control character}

        Semantics: The <delete statement> allows the user to define the
        character which, in control or message mode, causes the system
        to "forget" the previous line of input.  The default delete
        character is ASCII VT (control K).








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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


Transmit Statement

   <transmit statement> ::= TRANSMIT = {ASCII special or
                                        control character}

        Semantics: The <transmit statement> allows the user to define
        the character which, in control or message mode, causes the
        system to begin interpreting the control statement or to
        transmit the message.  The default transmit character is
        carriage return.

Lock Statement

   <lock statement> ::= LOCK

        Semantics: The <lock statement> causes the system to prevent any
        user or process but the process to which the user is currently
        attached from sending messages to the user's terminal.

Unlock Statement

   <unlock statement> ::= UNLOCK

        Semantics: The <unlock statement> reverses the action of a
        previous <lock statement>.

Assign Statement

   <assign statement> ::= ASSIGN <assign device> <q>

   <assign device>    ::= LP | DT | CP

        Semantics: The <assign statement> causes the system to attempt
        to assign a device not currently in use to the user.  The <q>
        construct has the same meaning as for the <link statement>.

Label Statement

   <label statement> ::? LABEL DT <device number> <tape label>

        Semantics: The <label statement> causes the system to write a
        new label on the DEC tape specified.









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RFC 76         Connection-By-Name: User-Oriented Protocol   October 1970


Create Statement

   <create statement> ::= CREATE <tape file name> ON <tape label>

        Semantics: The <create statement> causes the system to create a
        new file named <tape file name> on the DEC tape labeled <tape
        label>.

Purge Statement

   <purge statement> ::= PURGE <tape label> |

                         PURGE <tape file name> ON <tape label>

        Semantics: The <purge statement> causes the system to delete all
        tape directory information on the DEC tape or tape file
        specified.


           [ This RFC was put into machine readable form for entry ]
            [ into the online RFC archives by Gottfried Janik 2/98 ]






























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