The National Museum of Computing has welcomed a remarkable addition to its gallery, a machine so ancient and storied that it feels more like a time capsule than a piece of equipment. The world’s oldest computer has joined the museum’s collection, offering visitors a direct thread back to the dawn of digital calculation. The artifact is known as The WITCH, an acronym for Wolverhampton Instrument for Teaching Computation from Harwell. In the 1950s, engineers and scientists used this two ton behemoth to crunch vast numbers for frontier research, a task that today might seem almost quaint but was, at the time, transformative. The room where it operated hummed with vacuum tubes and relays, a tangible reminder that early computing lived at the edge of possibility. For audiences from Canada and the United States, The WITCH represents more than a historical curiosity; it is a concrete link to a global story of invention, collaboration, and the steady, often patient, climb from mechanical calculation to modern software and high-speed processing. The arrival of this machine invites visitors to imagine a world before personal computers and smartphones, when researchers and operators learned to coax logic from metal, and when every fix required careful, hands-on intervention. The WITCH’s presence in the NMOC collection emphasizes the museum’s mission to preserve critical pieces of digital heritage so future generations can study how computing began and how far it has come since those early, laborious days.
Named for its origin and purpose, The WITCH stands for Wolverhampton Instrument for Teaching Computation from Harwell. Built in the mid-twentieth century, this device played a pivotal role in showing that electronic computation could handle numbers at scales previously unimaginable, even if the speed of each calculation lagged behind modern expectations. In practice, a user would input a small sequence of digits, and the machine would perform a carefully choreographed sequence of operations that could take several seconds to reveal a result. It is a vivid reminder that progress in computing has always required balancing power, reliability, and human oversight. Although its operation sounds almost cinematic by today’s standards, the WITCH is a practical exemplar of early decimal computing, where each instruction moved through layers of circuits designed to reduce errors and maximize predictability. For visitors from Canada and the United States, the machine’s two ton mass and its patient cadence illustrate how international teams of researchers, engineers, and students pushed the boundaries of what machines could accomplish, laying the groundwork for the fast, interconnected systems that now underpin modern life. The WITCH thus stands not simply as a relic, but as a beacon of understanding—an object that helps explain how early ideas in computation matured into the digital ecosystem that powers global commerce, science, and everyday communication.
This long awaited revival of public life for The WITCH followed years of careful stewardship. The machine had been out of commission for about fifteen years, its operators and custodians waiting for the right moment to bring it back to life in a manner faithful to its original character. A dedicated cohort of computer historians, engineers, and volunteers undertook roughly three years of meticulous work, methodically inspecting every component, sourcing appropriate replacements where needed, and testing sustenance power and timing to ensure it would run as close as possible to its historic behavior. When the restoration concluded, the WITCH was reintroduced to the public in a form that preserved its authentic sound, rhythm, and feel, just as it would have appeared in its heyday. The revival is more than a mechanical reanimation; it is an educational event that invites curious minds from Canada, the United States, and beyond to observe the real-world constraints and ingenious workarounds that early operators used to keep a grand machine productive. For contemporary audiences, this demonstration underscores the NMOC’s role as a guardian of technology’s memory, providing a physical touchpoint with a past that informs today’s rapid advances in computing. By experiencing the restored WITCH, visitors gain a deeper appreciation for the journey from simple arithmetic devices to the sophisticated digital systems that drive science, industry, and everyday life across the North American and global landscape.