Electronic Business Magazine

Paternity suit – Father of the Microprocessor

After 30 years, Ray Holt is getting his chance to claim to be the father of the microprocessor. Are there lessons to be learned for today’s entrepreneurs?

Dean Takahashi — Electronic Business, 1/1/1999

Ray Holt will always remember the computer chips he designed for the U.S. Navy’s F-14A “Tomcat” fighter jet three decades ago. The top-secret project was the one chance he got to work with his younger brother Bill.

The young college graduates worked day and night on an engineering team from June 1968 to June 1970, creating the jet’s main flight computer. A few months after the work was finished, Bill Holt collapsed. Within 10 weeks, he died from a brain tumor at the age of 24. “I’ve always been glad I had the chance to work with him,” says Holt, 53, a computer consultant from San Jose. “We got along better than at any other time.”

Holt has been revisiting that bittersweet memory ever since April, when he won a 30-year battle with the Navy to declassify the project’s records, which, he believes, provide convincing evidence for his claim to the disputed title, “father of the microprocessor.” Forced to be silent for three decades, Holt hopes that now he and his team will get credit for their work, which he considers an electronics industry milestone. Interviews with Holt’s co-workers and his own documents confirm that their work preceded the 1969-1971 efforts of Santa Clara-based Intel Corp. that turned the microprocessor into a business empire. “It was very frustrating,” says Holt, about keeping silent for so long. “I almost had to forget about it.”

Now that he can talk about it, Holt is discovering how difficult it is to find a place in history after the books have been written. He doesn’t want riches. Holt wants only to be acknowledged enough to be granted a place in the high-tech industry’s pantheon of notable inventors, or, at least, a footnote in some history of important innovations.

“No footnote,” says Intel

But former Intel engineers Marcian “Ted” Hoff, Federico Faggin and Stan Mazor begrudge him even the footnote. They share credit as the microprocessor’s inventors because they put a complete central processing unit on a single chip, although one that was aided by three support chips. Moreover, their “4004” chip set was inexpensive and marketable as a versatile, general-purpose device that could be used to control a wide array of applications (though it was mainly designed for a calculator). Hoff doesn’t feel that Holt’s accomplishments threaten to displace him in history. “I still consider the 4004 as the first microprocessor,” he says. “[It was] the first computer central processor on a chip. In our view, it had to be a single chip.”

If Intel‘s cheap chip set was a Ford, Holt’s computer was more like a high-priced Cadillac, with three processor chips supported by three other chips. It had harder tasks to fulfill, such as calculating air speed, wing position and altitude simultaneously. Because of these mission requirements, Holt’s team couldn’t put everything on a single chip, and it would have been very difficult to build the processor as a cheap commercial product in 1970. Holt contends that doesn’t diminish his achievement, which could still be classified as the first microprocessor–one at least twice as powerful as Intel‘s first device. “It’s like you make 500 Cadillacs and can’t tell anybody about it,” Holt says. “Then somebody else builds a million Fords and now people are asking me why I didn’t build a Ford. [Intel] changed the world with it, but they were not the first.”

An athletic-looking man standing 5 feet 10 inches tall with a salt-and-pepper beard, Holt has the demeanor of an easy-going teacher. For the past 15 years he has worked as a systems integrator. He also trains people on how to use the Internet.

In the late 1960s, Holt was a B student in electrical engineering at California State Polytechnic University College in Pomona, CA. There he took one course on computer logic design, and that helped land him a job at Garrett AiResearch Corp., an aerospace contractor in Torrance, CA. The first day on the job, someone walked him over to an aircraft assembly line and showed him a large box with lots of gears, cams and wires. “They told me, ‘your job is to put all of that into a computer,’ ” Holt recalls.

That year, 1968, Robert Noyce and Gordon Moore formed Intel. IBM announced the floppy disk. And Bill Gates turned 13. Working closely with an older engineer named Steve Geller, Holt guided the team through the design of six chips that formed the brains of the computer. He had the help of a smart mathematician named Bill McCormick, who developed the set of equations for calculating the data needed for controlling the F-14’s aerodynamics, and he had the support of other top engineering talent. The team designed three processor chips to do “parallel” calculations because Holt decided a “programmed-serial,” or small-bytes-at-a-time, approach, like that used by Intel, would have been too slow. Intel used this kind of parallel approach in a co-processor in the late 1970s.

Holt’s work went on day and night, 12 hours a day, seven days a week for almost two years. Yet Holt, then in his early 20s, was driven because he felt that he was pushing the state of the art, and he had a tight deadline as well. Simple by today’s standards, the F-14A’s 375-kilohertz computer was a difficult undertaking. The chip design was intricately laid out on papers that covered an entire room. Since computer time to run simulations cost $1,800-an-hour then, much of the computing was done by hand. The pressure to get it right was extreme. If the chip set didn’t work, the jet might crash. Furthermore, the jet’s primary contractor, Grumman Corp., would lose $5,000 for each day it was late.

Holt was efficient but diplomatic in dealing with the engineers on the project, recalls James Lallas, a programmer on Holt’s team. “I was the complete opposite,” says Lallas. “But when I talked to Ray, my blood pressure would go down.” Lynn Hawkins, a technician who wired mock-ups together, recalls working furiously to finish the second prototype. Holt had accidentally burned out the chips on prototype number one when he plugged a power supply in backwards. “The generals were on an inspection and we got [prototype number two] to work when they were about 50 feet away,” recalls Hawkins.

Holt made his deadline, finishing work on the first design in late 1969. The first prototype worked 99.99%, with only one wrong programming instruction out of 65,000. Holt fixed the chip and, two months later, in November 1969, the first working prototype was made. Holt’s six-chip design included two chips for memory storage. The first F-14A Tomcat took off on December 21, 1970, almost a year before the debut of Intel‘s single chip microprocessor, the 4004.

While that is impressive, it doesn’t measure up to the resume of the 4004, which sparked the digital revolution that is still changing the world. Now that Holt has surfaced, industry experts are disputing the significance of his microprocessor. Faggin says that Holt’s flight computer, which would have been very expensive for non-aviation, commercial applications, probably would not have changed history at all. “If that is the case, then why is it important?” he asks.

Richard Belgard, a microprocessor expert in Saratoga, CA, says that Holt’s chip set is impressive, but its instruction set, which tells the processor what steps to perform, was somewhat limited to controlling an aircraft. Others say that Holt’s chip set doesn’t meet a common definition of a microprocessor: that is, a single-chip computer–a definition coined by Intel in the mid-70s. David Patterson, a professor of computer science at UC Berkeley, says, “No way is it a single-chip microprocessor.”

On the other hand, Holt says that the instruction set could be altered based on the chip configuration and application. Also, he notes that Intel Marketing Manager Hank Smith wrote in 1973 in an official paper for an engineering group, the Institute of Electrical and Electronics Engineers, that a central processing unit could contain “up to four standard large-scale integration chips.” By that definition, Holt’s three-processor chips constitute a microprocessor.

Tour de force

Another microprocessor expert thinks that Holt’s work was extremely significant. Russell Fish, a Dallas-based computer architect who worked on early Motorola microprocessors, agrees with Holt that the F-14A chips contained a number of inventions, including self-testing capability. Fish says a company with this technology could have become an Intel. “By any definition, [Holt’s design] was a technical tour de force of the first order,” Fish says.

In a way, Holt is lucky. He doesn’t have to deal with the hassle of being the first “usurper” to challenge Intel‘s place in history. That dubious distinction goes to Gilbert Hyatt, a Southern California engineer who, in 1990, won a patent for conceiving the first microprocessor in 1968. The Intel trio of Hoff, Faggin and Mazor reacted with hostility to him. Hyatt was deemed a carpetbagger because he never built more than one prototype, and he was reviled for trying to extract millions of dollars of royalties from companies that built the industry. Hyatt’s insistence spurred others to come out of the woodwork.

Gary Boone, who created Dallas-based Texas Instruments Inc.‘s first microprocessor in 1971, successfully challenged Hyatt’s patent, arguing that his chip couldn’t have been built to the specifications he outlined. The patent office canceled Hyatt’s patent, and an appeals court upheld the decision earlier this year.

Watching such shenanigans from the sidelines didn’t sour Holt’s fond memories about the project, which he associates with his last months with his brother. The two young men were very close and the loss was devastating. After his brother’s death, Holt found he couldn’t bear to go back to Garrett day in and day out.

The Navy never allowed Garrett (now part of AlliedSignal Inc., Morristown, NJ), to commercialize the chips or apply for patents on the technology. Holt wrote a design paper on the project for Computer Design magazine, but Garrett vetoed publication. Brice Maccubbin, a spokesman for the Naval Air Systems Command, says a thorough research of Navy records shows that the flight computer was not classified as a military secret, but it might have been a Garrett trade secret. But former Garrett team member Tom Redfern says “Ray isn’t crazy” when he says that the Navy didn’t want its secrets going out the door. “It was Navy classified,” says Redfern, now a technical fellow at National Semiconductor Corp., Santa Clara.

Holt put his design notebooks in a closet, but he tried to use his experience in commercial markets. He decided to move north, where he took a job at Pocatello, ID-based American Microsystems Inc. (AMI), now a subsidiary of Japan Energy Co. AMI had fabricated the flight computer’s chips. The distance helped put the pain of his brother’s death behind him. But Holt wasn’t destined for another milestone. After designing two more microprocessors, the AMI 7200 and 7300, AMI shut its microprocessor division in 1972, declaring its future was in custom chips.

Thrown out of work, Holt co-founded a small company, called Microcomputer Associates, that trained engineers how to design systems that used Intel‘s 4004 microprocessor. The job was not the same challenge as designing microprocessors, a let-down for someone who had invented something superior, but it paid the bills. He also designed several unique computer boards including the JOLT microcomputer kits, the SYM, a single-board computer, and he programmed the first microprocessor-controlled pinball game.

In the late 1970s, Holt dropped out of the design rat race. He was tired of “going to work when it was dark and coming home when it was dark.” He and his wife, Lynda, a teacher, were raising three sons. Always aware of his brother’s fate, he shifted to consulting so he could spend time with his family. He began helping people install and run computer systems, a job that he continues to this day.

In 1977, Holt founded the Christian Athletic Association, an athletic youth league. He devoted countless hours of volunteer time to the league. “The thing that is unusual about Ray is that he poured his life into something else when he could have become a millionaire with his trade,” says friend Ron Van Groningen, a San Jose resident. This work was a consolation when he saw others get credit for the microprocessor.

Holt tried to get the Navy to declassify the chip information in 1985, since, by then, the chips were obsolete and the newer models of the F-14 no longer used his computer. But without explanation, the Navy denied his request. “I was pretty angry and upset for some time,” Holt says. But Lynda Holt says she kept encouraging her husband to try again with the Navy, even though she didn’t know why it was important to him. “It was like he was outside looking in, when he should have been in,” she says.

Mark Holt, Ray’s 33-year-old eldest son, says his father honored the Navy’s request to keep the secret. He only learned about his father’s accomplishment a few months ago. “I knew he did the brain of the Tomcat,” Mark says. “I can imagine how difficult it was for my dad. He had to bite his tongue and wait, and meanwhile all these other people became demigods.”

Holt says he gave up trying to change the Navy’s mind and became absorbed in his work and the youth league. His son Mark believes that decision vastly improved their family life. “I saw a lot of families fall apart because people made wrong [career] decisions,” Mark says. “Our house was a gathering place when Dad started the youth league. In the long run, that was a bigger accomplishment.”


In April 1997, Holt appealed to the Navy again. This time, he consulted with his local congresswoman, Zoe Lofgren, a Democrat representing San Jose. With her assistance, Holt got to the right people in the Navy. This time, when he reached the Navy Captain in charge, “he laughed and said ‘Sure, we could declassify it.’ ” A year later, the Navy sent him a set of documents chronicling the chip’s invention, with a time stamp that said “approved for publication.”

Some of Holt’s records are still secret, pending approval from his former employer. Attorneys for Garrett have changed frequently, and the latest one said he had little time to review the materials. The company declined comment. Relieved he can talk about it, Holt has been having fun telling friends and family, and is gratified that they have no doubts about his honesty. “I was a little shocked when Ray told me,” says James Hook, a close friend. “He was very good about keeping it bottled up inside him for all those years. He worked like a dog, but I didn’t know he was there at the beginning [of that technology].”

Holt had a chance to explain his project publicly for the first time on September 26, 1998, at the Vintage Computer Festival in Santa Clara. A crowd of about 40 people, including some former members of the team, attended his presentation.

Holt’s son Mark has told his friends about his father’s accomplishment, but he understands what his father is up against. “It’s a big problem to fight 30 years of history,” he says.

Dean Takahashi is a technology reporter based in San Jose.

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