Ted Hoff’s General Purpose Microprocessor

“…even though science and technology are wonderful, what really gets them out there for people to use is to have businesses built around them. It takes savvy businessmen as well as savvy technologists to make that work.”

Tedd Hoff


Ted Hoff had access to then state-of-the-art vacuum tube circuits in high school. In 1954, he graduated and gained access to then-new transistors and magnetic core memory. Eventually, he earned a bachelor’s degree when came to Stanford, earning a Ph.D. in 1962.

During that time, he talked to Rex Rice, an on-campus recruiter for Fairchild Semiconductor. Particularly, the Traitorous Eight founded Fairchild and Doriot student Arthur Rock funded the business.

Hoff believed the new field of integrated circuits could work well for memory, replacing the clunky and relatively enormous core memory. Eventually, this led to a referral to Bob Noyce. He worked at Fairchild but was starting a new company, Intel. Evidently, Noyce intended Intel to focus on semiconductor memory and was searching for somebody with Hoff’s background.


In 1970, while waiting for the technology to mature, Intel decided to build one-off chips for the desktop calculator market. Eventually, Hoff was assigned to assist building a chip for Japanese company Busicom. At first, Japanese engineers were expected to do all the work with Hoff acting as a liaison and coordinator.

However, Hoff noticed the Japanese design was sub-optimal. There were about a dozen chips and the entire system appeared needlessly complex. Hoff raised his concerns to Noyce who encouraged him to make a “backup” design.

Hoff’s design incorporated random access memory and programmability. It was vastly simpler yet overall more powerful by being programmable rather than single-purpose. After a meeting, the customer adopted Hoff and Intel’s design.

Federico Faggin joined Intel and refined Hoff’s idea, optimizing the general-purpose chip to take advantage of Intel technology. By January 1971, the team had a fully functional microprocessor.

The Microprocessor is Born

Their original goal was an embedded system, not a PC chip. Embedded systems are specialty chips that people never see; they make other machines work. The final chip, renamed the Intel 4004, contained between 2,100 and 2,300 transistors, depending upon how one counted. In 1974, Intel’s 4004 was followed by the 8008 then the 8080. That chip became the foundation of the Altair, the first microcomputer. The Altair inspired a young Bill Gates and Co. to start a software company and a young Steve Jobs and Wozniak to form a computer company.

Electronic Desktop Calculator

Desktop calculators led the idea of computers small and cheap enough to sit on an individual’s desk. Eventually, they also became the impetus for the general-purpose microchip.


The first desktop electronic calculator is the ANITA Mark VII and ANITA Mark VIIII, both launched late 1961. The Bell Punch Co. of Britain designed the ANITA. Markedly, they used vacuum tubes and cold-cathode, and nixie tubes for the numerical display. Norbert (“Norman”) Kitz led the design and engineering work.

Eventually, the ANITA VII sold in continental Europe and the ANITA VIII in the UK and the rest of the world. However, soon after launch, Bell dropped the ANITA VII and consolidated the product line.

Cost was a major factor producing the ANITA. To make the calculator, Bell Punch needed to sell the product for about 1/100th the least expensive electronic computers of the day cost. Eventually, ANITA went on the market for £355 (about £7,800 in 2018, about $10,500 USD). In contrast, the least expensive general-purpose computers in 1961 cost about £50,000 (just over £1 million adjusted to 2018). The device weighed 34 pounds (15.5 kg).

Transistor-Based Calculators

Eventually, by 1964, competitors started to release calculators that used transistors rather than tubes. Sharp, Canon, Sony, Toshiba, Wang, and countless others released transistor-based calculators. However, these calculators were similarly priced to the ANITA, or even more expensive. Significantly, were significantly smaller and lighter due to the lack of tubes.

The Soviet Union literally weighed in with the T-64 built in Bulgaria. However, despite the use of semiconductors, the calculator weighed 8kg (17.6 lbs.) and is the first calculator to compute square roots.

Calculators continued to decrease in price, size, and increase in performance.

General-Purpose Microchip

Many calculator companies hired Intel, a young company, to produce custom chips for their calculators. Eventually,  in 1970, Intel engineer Ted Hoff instead created a general-purpose chip for Japanese company Busicom. Unlike other calculator chips, the Busicom chip was programmable to do multiple functions, not only those specific to one calculator. In 1971, Intel licensed the chip back and rebranded it the Intel 4004, Intel’s first general-purpose microprocessor.

Flash Memory

Flash memory stores and retrieves information more reliably and faster than hard drives. It works similar to RAM but is slower and far less expensive. It is fast, cheap, reliable, and virtually shock-proof.

Fuio Masuoka was a Toshiba employee. He developed a better type of solid-state memory and filed a patent in 1981.

His new chip allowed storage to reliably retain memory even without power.

No sooner did Toshiba release the new chip than Intel created their own and successfully commercialized it. Masuoka sued Intel for patent infringement and won $758,000 in 2006.

Flash memory – first used in thumb drives – today powers computers, phones, servers, and other electronics. In 2019, the global flash memory market was $61 billion.

Eventually, In 2017 Toshiba sold its chip business — primarily the lucrative flash memory business — to private equity firm led by Bain for $17.7 billion. The business was immensely profitable but a cash crunch forced Toshiba to sell.

Random Access Memory

Random Access Memory (RAM) is a type of fast memory. The Central Processing Unit (CPU), the brain of a computer, relies on RAM. RAM exists to this day. Every computer, including smartphones, contains RAM. The “random” in RAM refers to its ability to access memory anywhere, instantly, unlike a disk drive that must search for a piece of memory. This makes the memory much faster than disk drives.

Dennard’s RAM improved on core memory in that the individual units of storage were on silicon, not metal. This vastly miniaturized the memory, enabling countless units could be put on a chip.

However, unlike core memory, RAM has to be continually refreshed. Because the chips are made of silicon, they are fast enough to do this.

Although Dennard invented RAM as an IBM employee, it was Intel, a startup at that time, which most successfully commercialized the innovation.

Integrated Circuits (Microchips)

In early electronic computers, each circuit involved a vacuum tube. They were large, relatively slow, and consumed a lot of power.

Shockley, Brattain, and Bardeen created the semiconductor. Their circuits eliminated the need for vacuum tubes.

Kilby and Noyce discovered that semiconducting material held burned-in semiconductor circuits. Their printed circuits worked like the much larger metal counterparts. Furthermore, many circuits could be printed and tied together with a single piece of silicon.

These collections of circuits integrated on one chip are what we today refer to as microchips. You are reading this thanks to Kilby and Noyce’s invention.

Kilby worked for Texas Instruments. Noyce was one of the Traitorous Eight, the group who left the abusive, managerially incompetent Shockley. He was working at Fairchild Semiconductor, the firm funded by Doriot student Arthur Rock.

Kilby and Noyce never worked together but, at the same time, addressed the same problem. Kilby, tasked with shrinking the size of a semiconductor, thought of creating it from semiconducting material. He used geranium. Noyce realized that silicon worked better and that multiple circuits could be etched on one silicon wafer.

Their Integrated Circuit won the Nobel Prize in 2000 and went on to change the world. Noyce passed away in 1990 so only Kilby was eligible for the prize. Neither claimed sole credit nor disparaged the other.

Consequently, Kilby, a prolific innovator, was rewarded as an employee and led a comfortable life. Meanwhile, Noyce left Fairchild, co-founded Intel, and died a billionaire.