dtj v02-01 1990

This issue of the Digital Technical Journal, Volume 2, Number 1 (Winter 1990), is dedicated to Compound Document Architecture (CDA) developed by Digital Equipment Corporation.

The document's central theme is the development and implementation of CDA to address the growing need for seamless data interchange and integration of "compound documents" (containing text, graphics, images, and tabular data) across diverse applications, operating systems, and hardware in a heterogeneous network environment.

Key aspects covered include:

1. CDA Overview: Introduces CDA as a comprehensive, open, and extensible architecture designed to support the full lifecycle of compound documents. It details the foundational role of the revisable compound document model and the influence of industry and international standards.

2. Interchange Formats:

   • DDIS (Digital Data Interchange Syntax): The base meta-syntax for all CDA formats, based on ISO ASN.1, enabling compact, extensible, and computer-architecture-independent encoding.
   • DDIF (Digital Document Interchange Format): The primary CDA format for revisable text, graphics, and images, designed for high data portability, minimal storage, quality representation, and extensibility.
   • DTIF (Digital Table Interchange Format): Defines an application-independent and architecture-neutral format for revisable tabular data, including values, formulas, and presentation characteristics, addressing issues of revisability and internationalization.
   • DOTS (Data Object Transport Syntax): Used for electronic transfer of multiple related data elements.

3. CDA Services and Tools:

   • CDA Toolkit: A portable procedural library that provides applications with access to CDA documents (create, modify, read, write) and acts as a central "hub" for converting documents to and from non-CDA formats.
   • Converter Architecture: Layered on the toolkit, it supports dynamic conversion between CDA formats and other document formats.
   • Interapplication Access and Integration (LiveLink/AIL): Describes the Application Interface Library (AIL) for programmatic integration and DECdecision's Builder tool for user-level integration, enabling applications to share data and invoke each other dynamically.

4. CDA-Compliant Products/Applications:

   • DECdecision: A suite of end-user decision support applications (Access, Calc, DECchart, Builder, Control) that showcases CDA's capabilities by integrating data using DTIF and DDIF, leveraging DECwindows for its graphical user interface.
   • DECwrite Editor: Digital's WYSIWYG compound document editor, which uses DDIF as its native file format, demonstrating how a complex application can conform to DDIF's interchange goals while maintaining editing performance.
   • CDA in Science and Engineering (DECview3D): Illustrates CDA's extensibility to specialized domains, with DECview3D integrating 2D and 3D scientific and engineering graphics into compound documents, offering translation, viewing, and annotation capabilities.

The document emphasizes Digital's commitment to open standards, extensibility, and operating system independence as key factors in CDA's success, positioning it as a foundational architecture for distributed networking and future document processing needs, including new media types like voice and video.