Innovation does not happen in isolation; it is a battleground where ideas clash, rivalries ignite, and ownership defines the future. Behind the technologies we rely on every day lie stories of groundbreaking inventions entangled in fierce legal disputes. Patents have driven progress and sometimes stalled it. Welcome to Patent Feuds™. In this series, we uncover the rivalries that transformed industries, the inventions that triggered legal wars, and the lasting impact of Intellectual Property on the world. Get ready to explore the drama, the ambition, and the ideas that shaped modern history.

A World on the Brink of a Digital Age

By the late 1960s, the computer was no longer a scientific curiosity. Businesses were beginning to rely on it, universities were pushing its limits, and governments were weaving it into decision-making. The digital future felt inevitable. What few people realised, however, was that this future was quietly being threatened by a single patent, one that could have placed the entire computer industry under the control of one company.

That company was Sperry Rand, and it believed it owned the very foundation of electronic computing.

The Patent That Claimed the Computer

Sperry Rand’s confidence rested on U.S. Patent No. 3,120,606, titled “Electronic Numerical Integrator and Computer.” Granted in 1964 to engineers J. Presper Eckert and John Mauchly, the patent covered the ENIAC system, a machine widely celebrated as the first electronic digital computer.

ENIAC had been an engineering triumph of the wartime era, a room-sized machine filled with thousands of vacuum tubes, capable of performing calculations at unprecedented speeds. With control of the ENIAC patent, Sperry Rand believed it held rights not merely to a single machine, but to the basic architecture underlying all electronic digital computers. Armed with this belief, the company approached computer manufacturers across the industry with a clear message: if you build or use such computers, you owe us royalties.

Some companies choose to pay rather than challenge the claim. Others hesitated. One company refused.

Honeywell Draws a Line

Honeywell was unwilling to accept that one patent could dominate an entire industry. When Sperry Rand demanded licensing fees based on the ENIAC patent, Honeywell did more than say no; it went to court, challenging the very validity of U.S. Patent No. 3,120,606.

Rather than focusing on financial terms, Honeywell attacked the foundations of the patent itself. Their argument questioned not only ownership, but history.

Before ENIAC, There Was Atanasoff

Honeywell pointed to work that predated ENIAC by several years, carried out by physicist John Vincent Atanasoff and his graduate student Clifford Berry. Between 1939 and 1942, the pair developed the Atanasoff–Berry Computer, or ABC. Though never commercialized, the ABC introduced concepts that now define digital computing, including binary arithmetic, electronic logic, and a regenerative capacitor-based memory system.

Evidence presented at trial showed that John Mauchly had visited Atanasoff in 1941 and studied the ABC in detail. Letters, notes, and testimony suggested that key ideas from Atanasoff’s work influenced the later design of ENIAC. The court was not asked to decide whether ideas had been stolen, but whether ENIAC could legitimately claim to be the first electronic digital computer if it relied on earlier, un-credited innovations.

A Deadline Missed

Even apart from questions of originality, the ENIAC patent faced a serious legal problem. ENIAC was publicly demonstrated in February 1946, drawing widespread attention. However, the patent application for ENIAC was not filed until June 26, 1947. Under U.S. patent law, an inventor had only one year from public disclosure to file a patent application. That deadline had been exceeded.

In patent law, timing is unforgiving. Miss the filing window, and even a landmark invention can lose protection.

Six Years That Rewrote Computing History

From 1967 to 1973, the courtroom became a stage for revisiting the origins of computing. Engineers, historians, and legal experts dissected decades-old documents and technical designs. The trial blurred the line between legal analysis and historical inquiry, forcing the court to answer a question that had never before been formally addressed: who truly invented the electronic digital computer?

When Judge Earl R. Larson delivered his decision on October 19, 1973, the consequences were immediate and far-reaching. U.S. Patent No. 3,120,606 was declared invalid, primarily because the invention had been in public use for more than a year before the patent application was filed. The court also recognized Atanasoff as the originator of several fundamental concepts underlying electronic digital computing.

The Industry That Was Set Free

With the ENIAC patent invalidated, Sperry Rand’s claim to industry-wide royalties collapsed. The computer industry was suddenly free to innovate without fear of owing tribute to a single patent holder. Competition intensified, costs fell, and technological progress accelerated. The path was cleared for the rise of commercial computing, personal computers, and the digital economy that would follow.

Atanasoff, long overlooked in popular histories, finally received recognition for his pioneering contributions. More importantly, the ruling ensured that the basic architecture of computing remained a shared foundation rather than a privately owned idea.

Why This Patent Feud Still Matters

The Honeywell vs. Sperry Rand case remains one of the most important patent battles in history. It shows that patents can protect innovation, but when stretched too far, they can threaten progress itself. This feud reminds us that invention is rarely isolated, credit is often contested, and the future can hinge on whether someone is willing to challenge a powerful claim.

A single legal challenge to the ownership of the computer prevented a monopoly and unlocked the digital age.

At R K Dewan & Co., a leading Patent Law Firm in India, we provide reliable and professional patent services to protect your innovations. With over 80 years of experience, our expert team supports businesses in managing and enforcing patent rights across different industries and countries. We offer complete solutions, including Patent Search, patent filing, prosecution, and portfolio management. Trusted by top Indian companies and global organizations, we focus on delivering clear guidance and strong legal support. Our goal is to help inventors and businesses secure their ideas and grow with confidence in a competitive market.