Plan 28

Plan 28 is a long-term initiative aimed at constructing a complete, functional version of Charles Babbage's revolutionary Analytical Engine, a pioneering mechanical general-purpose computer designed in the 19th century. Launched in 2010 by programmer John Graham-Cumming, the project sought to realize Babbage's unbuilt vision through modern engineering, historical research, and public fundraising. It represents a significant endeavor in the history of computing, bridging the gap between Victorian-era mechanical calculation and contemporary digital technology. The project drew inspiration from the successful 1991 construction of Babbage's simpler Difference Engine No. 2 at the Science Museum, London.

Overview and Historical Context

The project is rooted in the pioneering work of Charles Babbage, a polymathic figure of the Industrial Revolution whose designs for mechanical computers were far ahead of their time. While Babbage's Difference Engine was intended for calculating mathematical tables, his more ambitious Analytical Engine, conceived in the 1830s, incorporated concepts fundamental to modern computing, such as an arithmetic logic unit, program control flow, and punched card-based memory and input, ideas later expanded upon by Ada Lovelace. For over a century, Babbage's designs remained theoretical curiosities, studied by historians like Allan G. Bromley and celebrated in works like *The Difference Engine*. The successful build of the Difference Engine No. 2, overseen by curator Doron Swade, demonstrated the feasibility of constructing Babbage's complex mechanisms, providing direct impetus for the more audacious goal of building the Analytical Engine.

The Plan 28 Project

Officially announced in 2010 on the 199th anniversary of Babbage's birth, the project was conceived and launched by John Graham-Cumming, a British computer scientist and author. The initiative was structured as a charitable project, seeking to methodically progress through distinct phases: exhaustive scholarly study of Babbage's original plans held at the Science Museum, London and other archives like the Bodleian Library, creation of a complete digital simulation, and finally, physical construction. A key early step was the digitization of Babbage's extensive notebooks and technical drawings, making them accessible for global research. The project's advisory board included prominent figures from computing history and engineering, such as Doron Swade and Tim Robinson.

Technical Specifications and Design

The Analytical Engine's design, as interpreted by the project, was a marvel of mechanical engineering intended to be powered by steam. Its architecture comprised several key components: the "Mill" (CPU), which performed arithmetic operations; the "Store" (memory), capable of holding thousands of numbers; and a system of punched cards for input and program sequencing, inspired by the Jacquard loom. A critical challenge for the project was resolving ambiguities and incomplete specifications in Babbage's evolving plans, which spanned decades. This required detailed analysis of his notebooks to understand the intended function of complex assemblies like the anticipatory carry mechanism and the precise interaction between the Mill, Store, and control barrel.

Funding and Public Engagement

The project was funded primarily through public donations via a dedicated website and a partnership with the Computer Conservation Society. It employed a crowdfunding model, encouraging small contributions from enthusiasts worldwide to become "supporters." This approach mirrored the public subscription model Babbage himself had attempted. High-profile endorsements and media coverage in outlets like The Guardian and *Wired* helped raise its profile. The project also engaged in public outreach through lectures at institutions like the Royal Institution and presentations at technology conferences, aiming to educate a broad audience on the origins of computing and Babbage's legacy.

Legacy and Current Status

While the full-scale physical Engine was not completed, Plan 28 succeeded in significantly advancing scholarly and public understanding of Babbage's most complex invention. The project's extensive digitization work created a vital, permanent resource for historians and engineers. It inspired other related projects and discussions within the history of computing community about the feasibility and value of constructing historical designs. As of the mid-2020s, the project is considered inactive, with its primary lasting contribution being the curated archive of Babbage's papers and the demonstration that public interest in foundational computing history remains strong. The dream of a working Analytical Engine continues to captivate engineers and historians, ensuring Babbage's and Lovelace's place in the narrative of technological evolution.

Category:History of computing Category:Charles Babbage Category:Computer projects