RFC 51 - Proposal for a Network Interchange Language

• Status: Unknown
• Published: 4 May 1970
• Stream: Legacy
• Errata: No Errata

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Document Information

• RFC Number: 51
• Title: Proposal for a Network Interchange Language
• Authors: M. Elie
• Date: 4 May 1970
• Category: Unknown

Abstract

RFC 51 proposes NIL (Network Interchange Language), a high level programming language intended for computer networks and more specifically for the ARPA network. Its central concept is an abstract Network Machine: the dialogue is always between a HOST and that machine, whose language is always the same although its configuration may vary according to the real remote HOST. NIL is subdivided into a control, an operation, a data declaration and an environment sublanguage, and a complete "program descriptor" would contain an environment, a data declaration, a control and an operation section. The data definition part of the paper defines significant fields, data beads (the smallest unit of data that can be referenced), an 8 bit FLAG field, POINTER and IDENTIFICATION fields and PARAMETER fields such as BEAMVT, all described in a COBOL-report-like metalanguage; it then proposes standard beads, both alphanumeric (CHAR, NUM, PRCHAR, ITCHAR, TRACHAR, DCCHAR, ALPH, PCCHAR) and graphic (MOVE, ARC), graphics parameters (SCALE, INT, SENS, BLINK, BEAM), the standard structure types VECTOR and PLEX, and standard objects such as SQUARE, COMSTRING, CODE, the binary card image, packed decimal numbers and decimal numbers. The paper is explicitly a proposal: it gives the syntax and the intended semantics of the standard beads rather than a fully specified language.

Table of Contents

• Introduction
• 1. Basic concepts introduced in NIL
  • 1.1 Aim of NIL
  • 1.2 NIL subcategorization
    • 1.2.1 Control sublanguage
    • 1.2.2 Operation sublanguage
    • 1.2.3 Data declaration sublanguage
    • 1.2.4 Environment sublanguage
  • 1.3 The Network Machine
  • 1.4 Implementation
• 2. Data definition sublanguage
  • 2.1 Fields
  • 2.2 Data beads.
  • 2.3 Control fields
    • 2.3.1 MODIFY field
    • 2.3.2 FLAG field
    • 2.3.3 POINTER field
    • 2.3.4 IDENTIFICATION field
    • 2.3.5 PARAMETER field
  • 2.4 Metalanguage definition
  • 2.5 Proposed standard beads
    • 2.5.1 Alphanumeric beads
      • Character: CHAR
      • Number representation
      • 1. Special Characters
      • 2. Subsets of Characters
    • 2.5.2 Graphic Beads
  • 2.6 Proposed parameter fields.
    • 2.6.1 Character strings.
    • 2.6.2 Graphics parameters
  • 2.7 Structures
    • 2.7.1 Structure definition.
    • 2.7.2 Standard structure type.
  • 2.8 Objects
    • 2.8.1 object definition.
    • 2.8.2 Alphanumeric standard objects.

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Related Resources

• Official RFC: RFC 51
• DataTracker: RFC 51 Info
• Errata: RFC Editor Errata