> The following excerpts are from the new edition of Fire In The Valley --

> EXCERPT TWO * The Transistor and the Nobel Prize
> EXCERPT THREE * DEC and Employee Desires
> EXCERPT FOUR * The First Hobbyist Personal Computer
> EXCERPT FIVE * Ed Roberts and the MITS Altair

> DEVELOPMENT OF THE MICROPROCESSOR
> Fire in the Valley describes the development of the microprocessor through the eyes of the people who did it:

> Moore & Noyce | In early 1969, Intel Development Corporation, a Silicon Valley semiconductor manufacturer, received a commission from a Japanese calculator company called Busicom to produce chips for a line of its calculators. Intel had the credentials: it was a Fairchild spinoff, and its president, Robert Noyce, had helped invent the integrated circuit. Although Intel had opened its doors for business only a few months earlier, the company was growing as fast as the semiconductor industry.
> An engineer named Marcian "Ted" Hoff had joined Intel a few months earlier as its twelfth employee, and when he began working on the Busicom job, the company already employed 200 people. Hoff was fresh from academia. After earning a Ph.D., he continued as a researcher at Stanford University's Electrical Engineering department, where his research on the design of semiconductor memory chips led to several patents and to the job at Intel. Noyce felt that Intel should produce semiconductor memory chips and nothing else, and he had hired Hoff to dream up applications for these memory chips. But when Busicom proposed the idea for calculator chips, Noyce allowed that taking a custom job while the company was building up its memory business wouldn't hurt. | Marcian "Ted" Hoff
> | Hoff was sent to meet with the Japanese engineers who came to discuss what Busicom had envisioned. Because Hoff had a flight to Tahiti scheduled for that evening, the first meeting with the engineers was brief. The trip evidently gave him time for contemplation, because he returned from paradise with some firm ideas about the job. In particular, he was annoyed that the Busicom calculator would cost almost as much as a minicomputer. Minicomputers had become relatively inexpensive, and research laboratories all over the country were buying them. It was not uncommon to find two or three minicomputers in a university's psychology or physics department. Hoff had worked with DEC's new PDP-8 computer, one of the smallest and cheapest of the lot, and found that it had a very simple internal setup. Hoff knew that the PDP-8, a computer, could do everything the proposed Busicom calculator could do and more for almost the same price. To Ted Hoff, this was an affront to common sense.
> Busicom Calculator | Hoff asked the Intel bosses why people should pay the price of a computer for something that had a fraction of the capacity. The question revealed his academic bias and his naivete about marketing: he would rather have a computer than a calculator, so he figured surely everyone else would, too. The marketing people patiently explained that it was a matter of packaging. If someone wanted to do only calculations, they didn't want to have to fire up a computer to run a "calculator" program. Besides, most people, even scientists, were intimidated by computers. A calculator was just a calculator from the moment you turned it on. A computer was an instrument from the Twilight Zone. Hoff could follow the reasoning, but nevertheless had a hard time swallowing the idea of building a special-purpose device when a general-purpose one was just as easy Ñ and no more expensive Ñ to build. Besides, he thought, a general-purpose design would make the project more interesting. He proposed a revised design loosely based on the PDP-8 to the Japanese engineers.
> The design's comparison to the PDP-8 computer was only partly applicable. Hoff was proposing a set of chips, not an entire computer. But one of those chips would be critically important in several ways. First, it would be dense. Chips at the time contained no more than 1,000 features - the equivalent of 1,000 transistors - but this chip would at least double that number. In addition, this chip would, like any IC, accept input signals and produce output signals. But whereas these signals would represent numbers in a simple arithmetic chip and logical values (true or false) in a logic chip, the signals entering and leaving Hoff's chip would form a set of instructions for the IC. In short, the chip could run programs. The customers were asking for a calculator chip, but Hoff was designing an IC EDVAC, a true general-purpose computing device on a sliver of silicon. A computer on a chip. Although Hoff's design resembled a very simple computer, it left out some computer essentials, such as memory and peripherals for human input and output. The term that evolved to describe such a device was microprocessor, and microprocessors were general-purpose devices specifically because of their programmability. Because the Intel microprocessor used the stored-program concept, the calculator manufacturers could make the microprocessor act like any kind of calculator they wanted. At any rate, that was what Hoff had in mind. He was sure it was possible, and just as sure that it was the right approach. But the Japanese engineers weren't impressed.
> Stan Mazor | Frustrated, Hoff sought out Noyce, who encouraged him to proceed anyway, and when chip designer Stan Mazor left Fairchild to go to Intel, Hoff and Mazor set to work on the design for the chip. At that point, Hoff and Mazor had not actually produced an IC. A semiconductor design specialist would still have to transform the design into a two-dimensional blueprint, and this pattern would have to be etched into a slice of silicon crystal. These later stages in the chip's development cost money, so Intel did not intend to move beyond the logic-design stage without talking further with its customers. In October 1969, skeptical Busicom representatives flew in from Japan to discuss the Intel project. The Japanese engineers presented their requirements, and in turn Hoff presented his and Mazor's design. Despite the fact that the requirements and design did not quite match, after some discussion Busicom decided to accept the Intel design for the chip. The deal gave Busicom an exclusive contract for the chips; not the best deal for Intel, but at least they were going ahead on the project.
> Hoff was relieved to have the go-ahead. They called the chip the 4004, which was the approximate number of transistors the single device replaced and an indication of its complexity. Hoff wasn't the only person ever to have thought of building a computer on a chip, but he was the first to launch a project that actually got carried out. Along the way, he and Mazor solved a number of design problems and fleshed out the idea of the microprocessor more fully. But there was a big distance between planning and execution.
> Leslie Vadasz, the head of a chip-design group at Intel, knew who he wanted to implement the design: Federico Faggin. Faggin was a talented chip designer who had worked with Vadasz at Fairchild and had earlier built a computer for Olivetti in Italy. The problem was, Faggin didn't work at Intel. Worse, he couldn't work at Intel, at least not right away: in the United States on a work visa, he was constrained in his ability to change jobs and still retain his visa. The earliest he would be available was the following spring. When Faggin came to Intel in April of 1970, he was immediately assigned to implement the 4004 design. Masatoshi Shima, an engineer for Busicom, was due to arrive to examine and approve the final design, and Faggin would set to work turning it into silicon. | Federico Faggin
> Unfortunately, the design was far from complete. Hoff and Mazor had completed the instruction set for the device and an overall design, but the necessary detailed design was nonexistent. Shima understood immediately that the "design" was little more than a collection of ideas. "This is just idea!" he shouted at Faggin. "This is nothing! I came here to check, but there is nothing to check!" Faggin confessed that he had only arrived recently, and that he was going to have to complete the design before starting the implementation. With help from Mazor and Shima, who extended his stay to six months, he did the job in a remarkably short time, working 12- to 16-hour days. Since he was doing something no one had ever done before, he found himself having to invent techniques to get the job done. In February 1971, Faggin delivered working kits to Busicom, including the 4004 microprocessor and eight other chips necessary to make the calculator work. It was a breakthrough, but its value was more in what it signified than in what it actually delivered. On the one hand, this new thing, the microprocessor, was nothing more than an extension of the IC chips for arithmetic and logic that semiconductor manufacturers had been making for years. The microprocessor merely crammed more functional capability onto one chip. Then again, there were so many functions that the microprocessor could perform, and they were integrated with each other so closely, that using the device required learning a new language, albeit a simple one. The instruction set of the 4004, for all intents and purposes, constituted a programming language.

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> Fire in the Valley by Paul Freiberger and Michael Swaine