At that time, Intel was making its money from memory chips and its marketing expert didn’t see any point in trying to sell the programmable chip to other people: “Look, computer companies sell 20 000 minicomputers a year. And we’re latecomers to the industry. If we’re lucky we’ll get 10 per cent. At 2000 chips a year, it’s just not worth all the trouble.” Michael Malone’s The Microprocessor charts the meteoric rise of the processor chip from these unpromising beginnings.

Malone believes the credit for the first microprocessor should really go to a man called Fredrico Faggin, previously unacknowledged. Intel wrote Faggin out of its history after he left in 1974, and instead gave all the credit to Ted Hoff, who initiated the development. But it was Faggin who led the teams that actually built the 4004 and the 8080. Earlier still, while at Fairchild, Faggin was one of the inventors of MOS (Metal Oxide Semiconductor) integrated circuit technology. He was the only person at Intel who could combine an understanding of chip architecture with the detailed practical knowledge required to convert these ideas into working devices.

Creating the first microprocessor was a great achievement, but it didn’t really involve much new technology. The key was the 1959 invention of the integrated circuit, combining transistors, resistors and capacitors on single “chips” of silicon. As pioneer Jack Kilby has said, the integrated circuit was genuinely unique in the world of inventions by being able to make a product more complex, more reliable and cheaper all at the same time.

By the late 1970s several companies were making microprocessor chips. Intel’s were generally less advanced than those of its rivals, but they were sold aggressively. The company even organised an “Operation Crush” in 1979 to try to wipe out some of its opposition. But its greatest coup was to sell microprocessors to IBM that same year.

IBM was intensely secretive about its planned “personal computer”. “When we went in to provide technical support, they’d have our people on one side of a black curtain and theirs on the other side with the prototype product,” says one Intel engineer who worked on the project. “We’d ask questions; they’d tell us what was happening and we’d have to try and solve the problem literally in the dark. If we were lucky, they’d let us reach a hand through the curtain and grope around a bit to try and figure what the problem was.”

It was the success of IBM’s PC that created Intel’s fortune and led it to dominate the market. Not that its products were ever perfect. I was delighted to find out that the virtual memory of the 286 was its inherent weakness – perhaps my ignorance and impatience were not the only reasons I could never get the extended or expanded memory software to work properly. The book brings the history right up to date, examining the highly publicised flaw in the Pentium that came to light last year, and goes into detail about today’s manufacturing process.

The statistics of a chip like the Pentium are extraordinary. Its silicon has to be “six nines purity”, that is 99.9999 per cent pure. If one track on the chip were to be enlarged to the width of an office corridor, the whole chip would be 100 miles wide. At the end of the manufacturing process, there is still some variability in the performance of the individual chips – for example, all 486s are made the same but are sorted on completion according to how fast they run, anything from 25 to 100 MHz. Clive Sinclair did the same sort of thing in the 1970s, buying reject military transistors to find ones that would still work well enough for his amplifiers.

The great advantage of the Complementary MOS technology used today is that it is scalable. The circuits and gates have been reduced in size from one generation of chips to the next and still work equally well when running on smaller voltages. This crams more circuitry into the same space while using less and less power.

Despite Intel’s aggressive marketing, Malone believes its dominance of the market is now challenged, particularly because its Pentium chip is not a RISC (reduced instruction set computer) microprocessor. RISC uses only simple instructions that can be executed in one clock cycle, allowing a chip to work much faster. More elaborate instructions are performed by sequences of the simple instructions. The Sun Sparkstation, Silicon Graphics computers and the Apple Power Macs all use RISC microprocessors.

Despite all the interesting facts and good stories in The Microprocessor, the book at times becomes an endless reel of chip numbers. Part of the interest in reading the history of something like the jet engine, the bridge or almost any other sort of technology, is puzzling out how they worked and why they improved things. The history of the microprocessor cannot provide this satisfaction. Malone does his best to explain the differences between them, but chips are the ultimate “black boxes”. They all look exactly the same, and there is no simple way of investigating what’s inside. In the late 1970s I bought an evaluation kit for a simple 6502 processor from the US. I spent many hours exploring the instructions in its memory and attempting to get it to do things. Eventually I got so frustrated I threw it out in disgust, but not before I had a good feel of how it was supposed to work. Most of today’s microprocessors are far too complex for this. Even a basic idea like RISC is not obvious: if the longer instructions are now done in sequences of short ones, they still take many machine cycles, so why is this any quicker?

The worst aspect of this book is its writing style. The hype is particularly irritating. No one doubts that the microprocessor is one of the most important inventions of the 20th century, but Malone’s assertions that there is one in every light switch, electric razor, hair dryer, refrigerator, electric toothbrush, coffee maker and pop-up toaster are absurd. I recently cut an example of each of these items in half for the new Secret Life of the Home gallery at the Science Museum in London. Not one contained a microprocessor. The “microchip” toaster just had a basic 555 timer chip inside, hardly a microprocessor. And even machines that do use microprocessors, such as video recorders, televisions and washing machines, have not changed that much. They are cheaper and have more features, but all of them were around long before microprocessors were added.

There is no need for any hype, and no shortage of evidence of the real influence of microprocessors.

One recent estimate suggested PCs consume 5 per cent of all industrial and commercial electricity.

The two factories I have visited in the past year were busy installing cheap microprocessor-based bits of automation. The managers of both factories felt they were fighting a battle to stay competitive with the Chinese, and could just about do so by using automation to reduce their labour costs.

Never one to understate things, Malone’s hype gets worse: “The microprocessor is giving us power over our lives … it is the greatest instrument of freedom ever invented.” Fax machines and computer modems may make it easier for people to communicate, but I doubt whether they have really ever been responsible for overthrowing totalitarian regimes, as he claims. Eventually the hype gets so bad it becomes entertaining: “The Industrial Revolution was set off by only a fifty times improvement in productivity. By comparison the microprocessor has improved its performance one thousand times in just 25 years. In other words the developers of the microprocessor have accomplished the equivalent of the Industrial Revolution every two and a half years.” If you can enjoy or ignore this sort of rubbish, then the book is worth a read.

This book was written as a textbook for US sixth form colleges and
universities, and funded by the Alfred P. Sloan foundation, a body set up to
foster ‘an understanding of technology and quantitive reasoning’ among
students. The authors are scientists who say the impulse to write the book
came from a realisation that most people do not relate directly to the
practice and findings of science but instead interact indirectly through
technology. The book takes the form of a series of case studies: telegraphy,
hydroelectric power, powered flight, electricity generation, oil refining,
pre-stressed concrete, vaccines, the greenhouse effect, and atomic power. It
looks at the history and development of each one, and at the science and
technology behind it.

They are all good stories, both epic and bizarre. For example, the inventor
of telegraphy’s Morse code, Samuel Morse, was not only an inventor, but also
a successful painter and politician. He was quite a repulsive character,
claiming credit for many other inventors’ contributions to the telegraph,
writing polemics against the Irish, Catholics and foreigners, and presiding
over a pro-slavery society.

In the last three case studies (vaccines, the greenhouse effect and atomic
power), the authors focus on the risks involved – they are almost a book
within a book. Each case is presented in a very clear and concise way, and
avoids the hysterical tone of much popular writing on the chosen topics. The
authors make the point that the science in each case has its limitations –
the problem both with low level radiation and atmospheric carbon dioxide is
that the risks involved are still largely unknown. For example, the chapter
on nuclear power ends with a quote from a Polish woman after Chernobyl: ‘At
first I was frightened, but now that I have heard all the explanations, I am
still frightened.’

The main theme of the book, however, is the relation between science and
engineering. When I was at school in the 1960s, science was certainly
regarded as superior to engineering (I was persuaded to do engineering by
the careers officer simply because he said I wasn’t bright enough to do
science). This attitude has its roots in the class system: science evolved
from natural philosophy, a respectable hobby for the rich, whereas
engineering evolved from mining, blacksmithing and other peasant activities.
I thought this was just a British problem, but judging by this book it is
also a problem in America.

The book also does a valuable job in debunking the commonly held view that
‘science is the font from which all technology springs’. In one or two of
the case studies, such as atomic power, the technology closely followed
scientific discovery, but in most, scientific method and theory were
developed only after the technology had been invented. The authors cite a US
military survey which found that only a tiny percentage of recent weapon
technologies benefited from basic scientific research.

I did, however, find the authors tendency to oversimplify issues irritating.
They make an unquestioned distinction between science as a ‘pure’ search for
nature’s patterns and inner workings, while the engineer tries to control
nature for human benefit, constrained by all sorts of social and financial
pressures. The distinction is much more blurred – most science today is
directed towards some practical application, even if obliquely, while many
engineers do ‘scientific’ experiments. The authors also distinguish between
an historical, the intuitive trial-and-error approach to technology and a
modern scientific, analytical approach. Again, although there is obviously
some truth in this, in reality modern engineers (and scientists) still need
intuition as much as analysis, and many uneducated 19th-century inventors
were quite analytical (illustrated in the book by the Wright brothers, who
even built their own wind tunnel for methodical testing).

These quibbles didn’t spoil my enjoyment. The stories are well worth reading
in their own right, and I also enjoyed being provoked into thinking about
the issues – even if I didn’t always agree with the authors.

Tim Hunkin writes about inventions and their history.