rfc732.txt

RFC 相关的技术文档

  where the quoted string is blinking.

  The terminal user is now free to fill in the form provided. He
  positions the cursor at the beginning of the first field (this usually
  is done by hitting the tab key) and begins typing. We do not show this
  interaction since it does not generate any interaction with the User
  Telnet program or the network. After the terminal user has completed
  filling in the form, he strikes the transmit key to send the
  unprotected part of the form, but first the User Telnet program
  negotiates the Byte Macro Option to condense the Field Separator
  subcommand:

  U:<IAC><DO><BM>                            [Negotiate Byte Macro
                                             Option.]

  S:<IAC><WILL><BM>                          [Define decimal 166 to be
                                             the Field Separator
                                             subcommand (see Appendix
                                             3)]







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Data Entry Terminal Option



  U:<IAC><SB><BM><DEFINE>
  <166><6><IAC SB DET FIELD
  SEPARATOR IAC SE><IAC><SE>

  S:<IAC><SB><BM><ACCEPT><166><IAC><SE>      [The server accepts the
                                             macro.]

  U:<IAC><SB><DET><DATA TRANSMIT><0><6><IAC><SE>
  John Doe <166> 1515 Elm St., Urbana, Il 61801
  <166> 217-333-9999 <166> 123-45-6789 <166>

  S:<IAC><SB><DET><ERASE SCREEN><IAC><SE>
  Thank you.

  And so on.





































John Day                                                       [page 24]

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Data Entry Terminal Option



Appendix 1 - Subcommands, opcodes and syntax

  1         EDIT FACILITIES      <Facilty map>
  2         ERASE FACILITIES     <Facility map>
  3         TRANSMIT FACILITIES  <Facility map>
  4         FORMAT FACILITIES    <Facility map 1> <Facility map 2>
  5         MOVE CURSOR          <x> <y>
  6         SKIP TO LINE         <y>
  7         SKIP TO CHAR         <x>
  8         UP
  9         DOWN
  10        LEFT
  11        RIGHT
  12        HOME
  13        LINE INSERT
  14        LINE DELETE
  15        CHAR INSERT
  16        CHAR DELETE
  17        READ CURSOR
  18        CURSOR POSITION      <x><y>
  19        REVERSE TAB
  20        TRANSMIT SCREEN
  21        TRANSMIT UNPROTECTED
  22        TRANSMIT LINE
  23        TRANSMIT FIELD
  24        TRANSMIT REST OF SCREEN
  25        TRANSMIT REST OF LINE
  26        TRANSMIT REST OF FIELD
  27        TRANSMIT MODIFIED
  28        DATA TRANSMIT <x><y>
  29        ERASE SCREEN
  30        ERASE LINE
  31        ERASE FIELD
  32        ERASE REST OF SCREEN
  33        ERASE REST OF LINE
  34        ERASE REST OF FIELD
  35        ERASE UNPROTECTED
  36        FORMAT DATA <format map>
  37        REPEAT     <count><char>
  38        SUPPRESS PROTECTION <negotiation>
  39        FIELD SEPARATOR
  40        FN <code>
  41        ERROR  <cmd><error code>









John Day                                                       [page 25]

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Data Entry Terminal Option



Appendix 2 - Error Codes

  1         Facility not previously negotiated.

  2         Illegal subcommand code.

  3         Cursor Address Out of Bounds.

  4         Undefined FN value.

  5         Can't negotiate acceptable line width.

  6         Can't negotiate acceptable page length.

  7         Illegal parameter in subcommand.

  8         Syntax error in parsing subcommand.

  9         Too many parameters in subcommand.

  10        Too few parameters in subcommand.

  11        Undefined parameter value

  12        Unsupported combination of Format Attributes



























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Data Entry Terminal Option



Appendix 3 - Use of the Byte Macro Option

  One of the major drawbacks of the DET option is that because the
  functions are encoded as Telnet option subnegotiations a fairly high
  overhead is incurred. A function like Character Insert which is
  encoded as a single byte in most terminals requires six bytes in the
  DET option. Originally the only other solution that would have
  accomplished the same transparency that the use of subcommands
  provides would have been to define additional Telnet control
  functions. However, since this would entail modification of the Telnet
  protocol itself, it was felt that this was not a wise solution. Since
  then the Telnet Byte Macro Option (RFC 729) has been defined. This
  option allows the user and server Telnets to map an arbitrary
  character string into a single byte which is then transferred over the
  net. Thus the Byte Macro Option provides the means for implementations
  to avoid the overhead for heavily used subcommands. The rest of this
  appendix suggests how the Byte Macro Option should be applied to the
  DET option.

  In keeping with the specification of the Byte Macro Option, macro
  bytes will be chosen from the range 128 to 239. For the DET option, it
  is suggested that macro bytes be chosen by adding the subcommand code
  to 128. In addition, an unofficial DET subcommand might be defined
  indicating that each side was willing to support macro bytes for all
  subcommands (but not necessarily support all of the subcommands
  themselves) according to this algorithm. This subcommand would be:

    IAC SB DET DET-MACRO <negotiation> IAC SE       subcommand code: 254

  where <negotiation> may have the values of the Telnet option
  negotiation:

    251     WILL
    252     WONT
    253     DO
    254     DONT

  This subcommand is sent by a Telnet implementation to indicate its
  willingness to adopt byte macros for all of the DET subcommands
  according to the following algorithm:

    The macro byte for subcommand i will be i+128 and will represent the
    following string for parameterless subcommands:

    IAC SB DET <subcommand code> IAC SE

    and the following string for subcommands with parameters:





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Data Entry Terminal Option



    IAC SB DET <subcommand code>

    The default setting for this subcommand is that the macros are not
    in effect, in other words,

      IAC SB DET DET-MACRO WONT IAC SE
      IAC SB DET DET-MACRO DONT IAC SE

    Negotiation of this subcommand follows the same rules as
    negotiations of the Telnet options.










































John Day                                                       [page 28]

NWG/RFC# 732                                  DAY 13-Sep-77 18:38  41762
Data Entry Terminal Option



References

  1.   ADM-1 Interactive Display Terminal Operator's Handbook
       Lear-Siegler, Inc. 7410-31.

  2.   ADM-Interactive Display Terminal Operator's Handbook
       Lear-Siegler, Inc. EID, 1974.

  3.   Burroughs TD 700/800 Reference Manual, Burroughs Corp., 1973

  4.   Burroughs TD 820 Reference Manual, Burroughs Corp. 1975.

  5.   CC-40 Communications Station: General Information Manual.
       Computer Communication, Inc. Pub. No. MI-1100. 1974.

  6.   Crocker, David. "Telnet Byte Macro Option," RFC 729, 1977.

  7.   Data Entry Virtual Terminal Protocol for Euronet, DRAFT, 1977.

  8.   Day, John. "A Minor Pitfall in the Telnet Protocol," RFC 728,
       1977.

  9.   Hazeltine 2000 Desk Top Display Operating Instructions. Hazeltine
       IB-1866A, 1870.

  10.  How to Use the Consul 980: A Terminal Operator's Guide and
       Interface Manual. Applied Digital Data Systems, Inc. 98-3000.

  11.  How to Use the Consul 520: A Terminal Operator's Guide and
       Interface Manual. Applied Digital Data Systems, Inc. 52-3000.

  12.  Honeywell 7700 Series Visual Information Projection (VIP)
       Systems: Preliminary Edition. 1973.

  13.  An Introduction to the IBM 3270 Information Display System. IBM
       GA27-2739-4. 1973.

  14.  Naffah, N. "Protocole Appareil Virtuel type Ecran" Reseau
       Cyclades. TER 536. 1976.

  15.  Postel, Jon and Crocker, David. "Remote Controlled Transmission
       and Echoing Telnet Option", RFC 726 NIC 39237, Mar. 1977.

  16.  Schicker, Peter. "Virtual Terminal Protocol (Proposal 2). INWG
       Protocol Note #32., 1976.







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Data Entry Terminal Option



  17.  UNISCOPE Display Terminal : Programmer Reference . Sperry- Univac
       UP-7807 Rev. 2, 1975.

  18.  Universal Terminal System 400: System Description. Sperry- Univac
       UP-8357, 1976.

  19.  Walden, David C. "Telnet Output Line Width Option." NIC # 20196,
       1973, also in ARPANET Protocol Handbook, 1976.

  20.  Walden, David C. "Telnet Output Page Size" NIC # 20197, 1973,
       also in ARPANET Protocol Handbook, 1976.









































John Day                                                       [page 30]