In Memoriam: Edward J. Mccluskey 1929 – 2016

Edward J. McCluskey, a professor of electrical engineering at Stanford University who was a pioneer of computer engineering, died Feb. 12 at the age of 86.

Born in New York City, McCluskey graduated from Bowdoin College in Maine in 1953 with a bachelor’s degree in mathematics and physics, before studying electrical engineering at the Massachusetts Institute of Technology (MIT), where he received bachelor’s and master’s degrees in the discipline in 1953, and a doctorate in 1956.

While a doctoral student, McCluskey extended an algorithm for minimization of boolean functions developed by W.V. Quine, which became known as the first algorithm for designing combinational circuits: the Quine-McCluskey logic minimization procedure. The algorithm continues to be used in design automation tools, and influenced most digital chips currently in use.

From 1955 through 1959, McCluskey worked as an intern at MIT, and later as a staff researcher at Bell Telephone Laboratories, where he worked on electronic switching systems. In 1959, McCluskey joined Princeton University to become a professor of electrical engineering and director of the university’s Computer Center.

At Bell Labs and Princeton, McCluskey developed the modern theory of transients (hazards) in logic networks and formulated the concept of operating modes of sequential circuits, which defined techniques for designing high-speed circuits.

In 1966, McCluskey left Princeton for Stanford, where he founded the Stanford Digital Systems Laboratory in (now called the Computer Systems Laboratory) in 1969. In 1970, he launched the Stanford Computer Engineering Program (now the Computer Science MS Degree Program).

Along with artificial intelligence pioneer Arthur Samuel and then-Stanford vice president and provost William Miller, McCluskey started the Stanford Computer Forum, a cooperative venture encouraging collaboration between Stanford’s computer science and the electrical engineering departments, and 60+ companies. The organization provides "a mechanism for developing interaction with industrial researchers and their academic counterparts, promoting the exchange of the most advanced technological ideas in fields of computer science and electrical engineering," and also "offers industry the opportunity to become familiar with the professional abilities and interests of Stanford students through its active recruiting program." McCluskey was director of the organization for its first eight years.  

In 1975, McCluskey launched the Center for Reliable Computing (CRC) at Stanford as part of the Computer Systems Laboratory. The CRC has been "involved in research on fault-tolerant computing, computer architecture, testing, and logic design," according to its website. McCluskey taught several courses each year in the CRC,  which included Logic Design, Testing Aspects of Computer Systems, Fault Tolerant Computing Systems, and a Digital Systems Reliability Seminar.

The CRC has made major contributions to the testing of computer chips, and helped design fault-tolerant systems to prevent computer crashes.

McCluskey’s research at Stanford was focused on logic testing, synthesis, design for testability, and fault-tolerant computing. With his students at the CRC, McCluskey worked out many key ideas for fault equivalence, probabilistic modeling of logic networks, pseudo-exhaustive testing, and watchdog processors. He collaborated with researchers at integrated circuits manufacturer Signetics to develop one of the first practical multivalued logic implementations, and then worked out a design technique for such circuitry.

Most recently, McCluskey was Emeritus Professor of Electrical Engineering and Computer Science at Stanford, and director of the CRC.

McCluskey mentored nine Ph.D.s at Princeton and 61 at Stanford. He wrote five books, and contributed chapters to 17 others.

Named the first president of the IEEE Computer Society in 1970, McCluskey was awarded the 1996 IEEE Emanuel R. Piore Award "for pioneering and fundamental contributions to design automation and fault tolerant computing," as well as the IEEE John von Neumann Medal in 2012 for providing "the foundation for the design automation methods that make production of today’s complex computer chips possible."

McCluskey was an IEEE Life Fellow (a fellow at least 65 years old, whose years of membership and age total at least 100). He also was a Fellow of ACM, and of the American association for the Advancement of Science (AAAS).

Among the researchers McCluskey helped to recruit to Stanford was the university’s current president, John Hennessy, who described McCluskey as "a pioneer in the computer engineering community." Hennessy said McCluskey was "a great educator, producing an incredible group of Ph.D. graduates, many of whom have gone on to become industry leaders. We were very fortunate to have him as our colleague. He will be deeply missed."

Unusual hats were a McCluskey trademark (a collection of thumbnail images shows him wearing headgear ranging from Mickey Mouse ears to Sherlock Holmes’ deerstalker hat), as was the green school bus which he bought to move his family across the U.S. from Princeton (New Jersey) to Stanford (northern California), and which he later used to take his family camping.

Robert K. Brayton, Cadence Distinguished Professor of Electrical Engineering and Computer Sciences at the University of California, Berkeley, recalled learning about McCluskey "through his work on two-level sum-of-products minimization and the Quine-McCluskey algorithm," which he described as "one of the few methods in logic synthesis in which one can say ‘that is a minimum result,’ and not just minimal."

Brayton said he met McCluskey at Berkeley. "I was always struck by what an open, welcoming, energetic jolly guy he was. He was an inspiration in both the technical and personal areas. His list of outstanding graduates produced over his time at Stanford is a record that will not be easily matched.

ACM president Alexander L. Wolf described McCluskey as "a storied engineer who made some of the most important and early contributions to computer hardware design. But he might well be most proud of having mentored and inspired several generations of computer scientists and engineers who followed him in advancing the discipline."

Lawrence M. Fisher is Senior Editor/News for ACM magazines.