Containers and Ultimate Portability

Initiated in the fall of 2025, the project's third and current stage is the culmination of the Decwar workflow evolution. The objective in this era is to free the entire system from any specific host hardware and achieve true simplicity and independence through containerization, creating a fully encapsulated digital artifact that can travel freely into the future. The architecture is a deliberate strategic decision to preserve the proven efficiency and authenticity of build-from-tape while leveraging containerization. The entire SIMH PDP-10 Decwar environment becomes a self-contained, portable ecosystem that can run on virtually any modern computer, whether it be a Raspberry Pi, a MacBook, a Windows machine, or a Cloud service. Once containerized, the system is "free to roam the Galaxy" and capable of running on any machine from a local laptop to a Cloud instance. The complex historical simulation is packaged into a simple, distributable artifact.

The architecture is a microservices-inspired, three component network managed by Docker Compose. Each component runs in its own container. On any machine with Python and Docker Engine, a user runs an install script once to pull the necessary Git repositories, and thereafter simply runs a start script to build and launch the entire three-container environment automatically. The only requirements are Python and the Docker Engine, making the entire workflow fundamentally portable. Three key technologies work in concert to deliver a seamless user experience. A Python script serves as the initial bootstrapper. It automates the one-time setup process by retrieving the Git repositories for generating the Docker containers. Docker is the core containerization technology that enables the encapsulation and isolation of the SIMH PDP-10 environment. It allows the complex legacy system and its dependencies to be packaged into a standardized and portable unit. Docker Compose is the orchestration tool used to define and run the multi-container system. It manages the networking and lifecycle of the individual containers, ensuring they launch and communicate as a single, cohesive system.

The environment is composed of three distinct Docker containers, each with a specialized role. Together, they form a complete, networked system for running and interacting with the Decwar game. The first container houses the reconstructed SDT and the SIMH PDP-10. It is responsible for the automated build of Decwar on every startup. The second container is both the primary controller and the primary API layer. It contains the main start script that initiates the entire Docker Compose system. It also provides the central REST API for controlling game robots. The third container is the presentation layer. It runs a web server that provides a visual interface to the running Decwar game by reading the central REST API to display game state.

This elegant three-container architecture separates concerns, making the system modular and manageable while providing a complete, end-to-end user experience and delivering tangible, transformative benefits for system development. By building upon the successes of the tape-based approach and leveraging modern containerization, the project provides a superior workflow that excels in portability, automation, and efficiency. Complete hardware abstraction is achieved by design. Unlike previous eras, which were tied to specific host configurations, the containerized system is entirely self-contained and capable of running on any machine that supports Python and the Docker Engine. This eliminates hardware dependencies and allows the development environment to be deployed consistently across developer laptops, testing servers, and cloud instances. Procedural, multi-step workflows are replaced with a declarative, single-command system activation. The entire lifecycle of the environment, from fetching source code to building the SIMH PDP-10 system and launching all necessary services, is condensed into a single start script. This push button simplicity drastically reduces setup time, eliminates the potential for human error, and makes the system accessible to those unfamiliar with the underlying DEC PDP-10 architecture. The project’s architecture inherits and perfects the speed of the tape-based workflow. The process of creating a tape image remains nearly instantaneous, and the SIMH PDP-10 Decwar startup and build cycle completes in seconds. By containerizing this already-efficient process and automating it end-to-end, the fastest, most reliable, and most repeatable development cycle is achieved. These combined benefits represent a paradigm shift, moving the historical artifacts from a specialist's pursuit into the realm of modern, professional engineering.