Design Workbench Research Articles

Designer's Workbench: The Programmer Environment

Designer's Workbench, based on the PWB/UNIX <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> operating system, is a software system that provides a high level interface to the circuit design aids used within Bell Laboratories. As well as providing a convenient environment for the use of these applications, a primary goal in the design of DWB was to provide a convenient and versatile environment in which programmers could work. This paper describes the objectives that were defined to reach this goal. The approach was to simplify the addition of new capabilities to the system, realizing that a viable design-aids system must be able to expand with the increased demand for and complexity of the applications it supports. We discuss in detail the methods and mechanisms used in the development and implementation of the system. Although some of these are specific to the functions required by DWB, the general philosophies that are emphasized can be applied to provide a programming environment for any software system.

Designer's Workbench: Philosophy

Designer's Workbench (DWB) increases the productivity of the design-aids user by buffering the user from the idiosyncrasies of the application programs and the computers on which they run. These aids are used during the electrical design, physical design, and test development of both custom electronics and printed wiring boards. The design-aids programs were left unchanged on their original computers and are accessed via an interlocation computing network using the capabilities of the PWB/UNIX <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∗</sup> operating system. All job control, file management, and data translation required for the programs are provided automatically. In addition to describing the design constraints applied during the development of DWB, this paper also introduces the three other papers in this issue that describe in detail the user, programmer, and production environments created by DWB.

A Prototype Program Design Workbench

This paper describes current work in defining and developing a CASE tool to support program design. This work is proceeding alongside a parallel effort to produce a comprehensive set of separate but cooperating tools for use in teaching programming to undergraduate students, based on the use of a formally defined program design language, provisionally called MFC (Modular Pseudocode). The CASE tool, which we call the Program Design Workbench (PDW), is intended to help integrate the use of MPC tools through a convenient windowed user interface, but much more importantly it will embody and enforce a disciplined and methodical approach to modular program design. In addition, the PDW will eventually manage a collection of design databases and allow controlled access to and navigation between design objects. The prototype is being developed using the IPSYS ToolBuilder meta-CASE tool. The target methodology is captured in terms of a data model and a frames model. The former defines the structure. attributes and possible inter-relationships of design objects, and is used to generate the PDW design database: while the latter defines the available operations and allowable context transitions in the generated graphical user interface. In this paper we explain both aspects and highlight the continuing development work of the associated methodology.