Browse Prior Art Database

Decode Encode Language (DEL) (RFC0005) Disclosure Number: IPCOM000003635D
Original Publication Date: 1969-Jun-02
Included in the Prior Art Database: 2001-Oct-17
Document File: 17 page(s) / 28K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Rulifson: AUTHOR


The Decode-Encode Language (DEL) is a machine independent language tailored to two specific computer network tasks:

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 13% of the total text.

Network Working Group                                           4691

RFC-5                                                           Jeff Rulifson

                                                                June 2, l969


:DEL, 02/06/69 1010:58   JFR   ;   .DSN=1; .LSP=0; ['=] AND NOT SP ; ['?];

dual transmission?


   The Decode-Encode Language (DEL) is a machine independent language

   tailored to two specific computer network tasks:

      accepting input codes from interactive consoles, giving immediate

      feedback, and packing the resulting information into message

      packets for network transmissin.

      and accepting message packets from another computer, unpacking

      them, building trees of display information, and sending other

      information to the user at his interactive station.

   This is a working document for the evolution of the DEL language.

   Comments should be made through Jeff Rulifson at SRI.


   The initial ARPA network working group met at SRI on October 25-26,


      It was generally agreed beforehand that the runmning of interactive

      programs across the network was the first problem that would be


      This group, already in agreement about the underlaying notions of

      a DEL-like approach, set down some terminology, expectations for

      DEL programs, and lists of proposed semantic capability.

      At the meeting were Andrews, Baray, Carr, Crocker, Rulifson, and


   A second round of meetings was then held in a piecemeal way.

      Crocker meet with Rulifson at SRI on November 18, 1968.  This

      resulted in the incorporation of formal co-routines.

      and Stoughton meet with Rulifson at SRI on Decembeer 12, 1968.  It

      was decided to meet again, as a group, probably at UTAH, in late

      January 1969.

   The first public release of this paper was at the BBN NET meeting in

   Cambridge on February 13, 1969.


   NST   The NST library is the set of programs necessary to mesh

   efficiently with the code compiled at the user sites from the DEL

   programs it receives.  The NST-DEL approach to NET interactive system

   communication is intended to operate over a broad spectrum.

   The lowest level of NST-DEL usage is direct transmission to the

   server-host, information in the same format that user programs

   would receive at the user-host.

      In this mode, the NST defaults to inaction.  The DEL program

      does not receive universal hardware representation input but

      input in the normal fashion for the user-host.

      And the DEL 1 program becomes merely a message builder and


   A more intermediate use of NST-DEL is to have echo tables for a

   TTY at the user-host.

      In this mode, the DEL program would run a full duplex TTY for

      the user.

      It would echo characters, translate them to the character set

      of the server-host, pack the translated characters in messages,

      and on appropriate break characters send the messages.

      When messages come from the server-host, the DEL program would

      translate them to the user-host character set and print them on

      his TTY.

   A more ambitious task for DEL is the operation of large,

   display-oriented systems from remote consoles over the NET.

      Large interactive systems usually offer a lot of feedback to

      the user.  The unusual natur...