Engines of Calculation
Neither the abacus, nor the mechanical calculators constructed by
Pascal and Leibniz really qualified as computers. A calculator is a
device that makes it quicker and easier for people to do sums—but it
needs a human operator. A computer, on the other hand, is a machine
that can operate automatically, without any human help, by following a
series of stored instructions called a program (a kind of mathematical
recipe). Calculators evolved into computers when people devised ways of
making entirely automatic, programmable calculators.
Photo: Punched cards: Herman Hollerith perfected the way of using punched cards
and paper tape to store information and feed it into a machine. Here's a drawing from his 1889 patent
Art of Compiling Statistics (US Patent#395,782),
showing how a strip of paper (yellow) is punched with different patterns of holes (orange) that correspond to
statistics gathered about people in the US census. Picture courtesy of US Patent and Trademark Office.
The first person to attempt this was a rather obsessive, notoriously
grumpy English mathematician named Charles Babbage
(1791–1871). Many regard Babbage as the "father of the computer"
because his machines had an input (a way of feeding in numbers), a
memory (something to store these numbers while complex calculations
were taking place), a processor (the number-cruncher that carried out
the calculations), and an output (a printing mechanism)—the same basic
components shared by all modern computers. During his lifetime, Babbage
never completed a single one of the hugely ambitious machines that he
tried to build. That was no surprise. Each of his programmable
"engines" was designed to use tens of thousands of precision-made
gears. It was like a pocket watch scaled up to the size of a steam
engine, a Pascal or Leibniz machine magnified a thousand-fold in
dimensions, ambition, and complexity. For a time, the British
government financed Babbage—to the tune of £17,000, then an
enormous sum. But when Babbage pressed the government for more money to
build an even more advanced machine, they lost patience and pulled out.
Babbage was more fortunate in receiving help from Augusta
Ada Byron (1815–1852), Countess of Lovelace, daughter of the
poet Lord Byron. An enthusiastic mathematician, she helped to refine
Babbage's ideas for making his machine programmable—and this is why she
is still, sometimes, referred to as the world's first computer
 Little of Babbage's work survived after his death. But
when, by chance, his notebooks were rediscovered in the 1930s, computer
scientists finally appreciated the brilliance of his ideas.
Unfortunately, by then, most of these ideas had already been reinvented
Artwork: Charles Babbage (1791–1871). Picture from The Illustrated London News, 1871, courtesy of US Library of Congress.
Babbage had intended that his machine would take the drudgery out of
repetitive calculations. Originally, he imagined it would be used by
the army to compile the tables that helped their gunners to fire
cannons more accurately. Toward the end of the 19th century, other
inventors were more successful in their effort to construct "engines"
of calculation. American statistician Herman
Hollerith (1860–1929) built one of the world's first practical
calculating machines, which he called a tabulator, to help compile
census data. Then, as now, a census was taken each decade but, by the
1880s, the population of the United States had grown so much through
immigration that a full-scale analysis of the data by hand was taking
seven and a half years. The statisticians soon figured out that, if
trends continued, they would run out of time to compile one census
before the next one fell due. Fortunately, Hollerith's tabulator was an
amazing success: it tallied the entire census in only six weeks and
completed the full analysis in just two and a half years. Soon
afterward, Hollerith realized his machine had other applications, so he
set up the Tabulating Machine Company in 1896 to manufacture it
commercially. A few years later, it changed its name to the
Computing-Tabulating-Recording (C-T-R) company and then, in 1924,
acquired its present name: International Business Machines (IBM).
Photo: Keeping count: Herman Hollerith's late-19th-century census machine (blue, left) could process 12 separate bits of statistical data each minute. Its compact 1940 replacement (red, right), invented by Eugene M. La Boiteaux of the Census Bureau, could work almost five times faster. Photo by Harris & Ewing courtesy of US Library of Congress.
Bush and the bomb
Photo: Dr Vannevar Bush (1890–1974).
Picture by Harris & Ewing, courtesy of US Library of Congress.
The history of computing remembers colorful characters like Babbage,
but others who played important—if supporting—roles are less well
known. At the time when C-T-R was becoming IBM, the world's most
powerful calculators were being developed by US government scientist Vannevar Bush (1890–1974). In 1925, Bush made the
first of a series of unwieldy contraptions with equally cumbersome
names: the New Recording Product Integraph Multiplier. Later, he built
a machine called the Differential Analyzer, which used gears, belts,
levers, and shafts to represent numbers and carry out calculations in a
very physical way, like a gigantic mechanical slide rule. Bush's
ultimate calculator was an improved machine named the Rockefeller
Differential Analyzer, assembled in 1935 from 320 km (200 miles) of
wire and 150 electric motors. Machines
like these were known as analog calculators—analog because they stored
numbers in a physical form (as so many turns on a wheel or twists of a
belt) rather than as digits. Although they could carry out incredibly
complex calculations, it took several days of wheel cranking and belt
turning before the results finally emerged.
Impressive machines like the Differential Analyzer were only one of
several outstanding contributions Bush made to 20th-century technology.
Another came as the teacher of Claude Shannon
(1916–2001), a brilliant mathematician who figured out how electrical
circuits could be linked together to process binary code with Boolean
algebra (a way of comparing binary numbers using logic) and thus make
simple decisions. During World War II, President Franklin D. Roosevelt
appointed Bush chairman first of the US National Defense Research
Committee and then director of the Office of Scientific Research and
Development (OSRD). In this capacity, he was in charge of the Manhattan
Project, the secret $2-billion initiative that led to the creation of
the atomic bomb. One of Bush's final wartime contributions was to
sketch out, in 1945, an idea for a memory-storing and sharing device
called Memex that would later inspire Tim Berners-Lee to invent the
World Wide Web.
 Few outside the world
of computing remember Vannevar Bush today—but what a legacy! As a
father of the digital computer, an overseer of the atom bomb, and an
inspiration for the Web, Bush played a pivotal role in three of the
20th-century's most far-reaching technologies.
Photo: "A gigantic mechanical slide rule": A differential analyzer pictured in 1938.
Picture courtesy of and © University of Cambridge
Computer Laboratory, published with
via Wikimedia Commons
Creative Commons (CC BY 2.0)
Many of the pioneers of computing were hands-on experimenters—but by no means all of them.
One of the key figures in the history of 20th-century computing, Alan Turing (1912–1954) was
a brilliant Cambridge mathematician whose major contributions were to the theory of how
computers processed information. In 1936, at the age of just 23, Turing wrote
a groundbreaking mathematical paper called "On computable numbers, with an application to the Entscheidungsproblem,"
in which he described a theoretical computer now known as a
Turing machine (a simple information processor that works through a series of instructions,
reading data, writing results, and then moving on to the next instruction).
Turing's ideas were hugely influential in the years that followed and many people
regard him as the father of modern computing—the 20th-century's equivalent of Babbage.
Although essentially a theoretician, Turing did get involved with real, practical machinery,
unlike many mathematicians of his time. During World War II, he played a pivotal role in the development of code-breaking
machinery that, itself, played a key part in Britain's wartime victory; later, he played a lesser role
in the creation of several large-scale experimental computers including
ACE (Automatic Computing Engine), Colossus, and the Manchester/Ferranti Mark I (described below).
Today, Alan Turing is best known for conceiving what's become known as the Turing test, a simple
way to find out whether a computer can be considered intelligent by seeing whether it can
sustain a plausible conversation with a real human being.
The first modern computers
The World War II years were a crucial period in the history of
computing, when powerful gargantuan computers began to appear. Just
before the outbreak of the war, in 1938, German engineer Konrad Zuse (1910–1995) constructed his Z1, the
world's first programmable binary computer, in his parents' living
 The following year, American physicist John
Atanasoff (1903–1995) and his assistant, electrical engineer Clifford Berry (1918–1963), built a more elaborate
binary machine that they named the Atanasoff Berry Computer (ABC). It
was a great advance—1000 times more accurate than Bush's Differential
Analyzer. These were the first machines that used
electrical switches to store numbers: when a switch was "off", it
stored the number zero; flipped over to its other, "on", position, it
stored the number one. Hundreds or thousands of switches could thus
store a great many binary digits (although binary is much less
efficient in this respect than decimal, since it takes up to eight
binary digits to store a three-digit decimal number). These machines
were digital computers: unlike analog machines, which stored numbers
using the positions of wheels and rods, they stored numbers as digits.
The first large-scale digital computer of this kind appeared in 1944
at Harvard University, built by mathematician Howard
Aiken (1900–1973). Sponsored by IBM, it was variously known as
the Harvard Mark I or the IBM Automatic Sequence Controlled Calculator
(ASCC). A giant of a machine, stretching 15m (50ft) in length, it was
like a huge mechanical calculator built into a wall. It must have sounded
impressive, because it stored and processed numbers using
"clickety-clack" electromagnetic relays (electrically operated
that automatically switched lines in telephone exchanges)—no fewer than
3304 of them. Impressive they may have been, but relays suffered from
several problems: they were large (that's why the Harvard Mark I had to
be so big); they needed quite hefty pulses of power to make them switch;
and they were slow (it took time for a relay to flip from "off" to "on"
or from 0 to 1).
Photo: An analog computer being used in military
research in 1949. Picture courtesy of
NASA on the Commons (where you can download a larger version.
Most of the machines developed around this time were intended for
military purposes. Like Babbage's never-built mechanical engines, they
were designed to calculate artillery firing tables and chew through the
other complex chores that were then the lot of military mathematicians.
During World War II, the military co-opted thousands of the best
scientific minds: recognizing that science would win the war, Vannevar
Bush's Office of Scientific Research and Development employed 10,000
scientists from the United States alone. Things were very different in
Germany. When Konrad Zuse offered to build his Z2 computer to help the
army, they couldn't see the need—and turned him down.
On the Allied side, great minds began to make great breakthroughs.
In 1943, a team of mathematicians based at Bletchley Park near London,
England (including Alan Turing) built a computer called Colossus to help them crack secret
German codes. Colossus was the first fully electronic computer. Instead
of relays, it used a better form of switch known as a vacuum tube (also
known, especially in Britain, as a valve). The vacuum tube, each one about
as big as a person's thumb (earlier ones were very much bigger) and glowing red hot like a tiny electric
light bulb, had been invented in 1906 by Lee de
Forest (1873–1961), who named it the Audion. This
breakthrough earned de Forest his nickname as "the father of radio" because their first major
use was in radio receivers, where they amplified weak incoming signals
so people could hear them more clearly.
 In computers such as the ABC
and Colossus, vacuum tubes found an alternative use as faster and more
Just like the codes it was trying to crack, Colossus was top-secret
and its existence wasn't confirmed until after the war ended. As far as
most people were concerned, vacuum tubes were pioneered by a more
visible computer that appeared in 1946: the Electronic Numerical
Integrator And Calculator (ENIAC). The ENIAC's inventors, two
scientists from the University of Pennsylvania, John
Mauchly (1907–1980) and J. Presper Eckert
(1919–1995), were originally inspired by Bush's Differential Analyzer;
years later Eckert recalled that ENIAC was the "descendant of Dr Bush's
machine." But the machine they constructed was far more ambitious. It
contained nearly 18,000 vacuum tubes (nine times more than Colossus),
was around 24 m (80 ft) long, and weighed almost 30 tons. ENIAC is
generally recognized as the world's first fully electronic,
general-purpose, digital computer. Colossus might have qualified for
this title too, but it was designed purely for one job (code-breaking);
since it couldn't store a program, it couldn't easily be reprogrammed to do other things.
Photo: Sir Maurice Wilkes (left), his collaborator William
Renwick, and the early EDSAC-1 electronic computer they built in Cambridge, pictured
around 1947/8. Picture courtesy of and © University of Cambridge
Computer Laboratory, published with
via Wikimedia Commons
Creative Commons (CC BY 2.0)
ENIAC was just the beginning. Its two inventors formed the Eckert
Mauchly Computer Corporation in the late 1940s. Working with a
brilliant Hungarian mathematician, John von Neumann
(1903–1957), who was based at Princeton University, they then designed
a better machine called EDVAC (Electronic Discrete Variable Automatic
Computer). In a key piece of work, von Neumann helped to define how the
machine stored and processed its programs, laying the foundations for
how all modern computers operate.
After EDVAC, Eckert and Mauchly developed UNIVAC 1 (UNIVersal Automatic Computer) in 1951. They were
helped in this task by a young, largely unknown American mathematician
and Naval reserve named Grace Murray Hopper
(1906–1992), who had originally been employed by Howard Aiken on the
Harvard Mark I. Like Herman Hollerith's tabulator over 50 years before,
UNIVAC 1 was used for processing data from the US census. It was then
manufactured for other users—and became the world's first large-scale
Machines like Colossus, the ENIAC, and the Harvard Mark I compete
for significance and recognition in the minds of computer historians.
Which one was truly the first great modern computer? All of them and
none: these—and several other important machines—evolved our idea of
the modern electronic computer during the key period between the late
1930s and the early 1950s. Among those other machines were pioneering
computers put together by English academics, notably the Manchester/Ferranti Mark I,
built at Manchester University by Frederic Williams
(1911–1977) and Thomas Kilburn (1921–2001),
and the EDSAC (Electronic Delay Storage Automatic Calculator), built by
Maurice Wilkes (1913–2010) at Cambridge
Photo: Control panel of the UNIVAC 1, the world's first large-scale
Photo by Cory Doctorow published on
Flickr in 2020 under a Creative Commons (CC BY-SA 2.0) licence.
The microelectronic revolution
Vacuum tubes were a considerable advance on relay switches, but
machines like the ENIAC were notoriously unreliable. The modern term
for a problem that holds up a computer program is a "bug." Popular
legend has it that this word entered the vocabulary of computer
programmers sometime in the 1950s when moths, attracted by the glowing
lights of vacuum tubes, flew inside machines like the ENIAC, caused a
short circuit, and brought work to a juddering halt. But there were
other problems with vacuum tubes too. They consumed enormous amounts of
power: the ENIAC used about 2000 times as much electricity as a modern
laptop. And they took up huge amounts of space. Military needs were
driving the development of machines like the ENIAC, but the sheer size
of vacuum tubes had now become a real problem. ABC had used 300 vacuum
tubes, Colossus had 2000, and the ENIAC had 18,000. The ENIAC's
designers had boasted that its calculating speed was "at least 500
times as great as that of any other existing computing machine." But
developing computers that were an order of magnitude more powerful
still would have needed hundreds of thousands or even millions of
vacuum tubes—which would have been far too costly, unwieldy, and
unreliable. So a new technology was urgently required.
Photo: A typical transistor on an electronic circuit board.
The solution appeared in 1947 thanks to three physicists working at
Bell Telephone Laboratories (Bell Labs). John
Bardeen (1908–1991), Walter Brattain
(1902–1987), and William Shockley (1910–1989)
were then helping Bell to develop new technology for the American
public telephone system, so the electrical signals that carried phone calls could be
amplified more easily and carried further. Shockley, who was leading the team, believed
he could use semiconductors (materials such as germanium and silicon
that allow electricity to flow through them only when they've been
treated in special ways) to make a better form of amplifier than the vacuum tube.
When his early experiments failed, he set Bardeen and Brattain to work
on the task for him. Eventually, in December 1947, they created a new
form of amplifier that became known as the point-contact transistor.
Bell Labs credited Bardeen and Brattain with the transistor and awarded
them a patent. This enraged Shockley and prompted him to invent an even
better design, the junction transistor, which has formed the basis of
most transistors ever since.
Like vacuum tubes, transistors could be used as amplifiers or as
switches. But they had several major advantages. They were a fraction
the size of vacuum tubes (typically about as big as a pea), used no
power at all unless they were in operation, and were virtually 100
percent reliable. The transistor was one of the most important
breakthroughs in the history of computing and it earned its inventors
the world's greatest science prize, the
1956 Nobel Prize in Physics.
By that time, however, the three men had already gone their
separate ways. John Bardeen had begun pioneering research into
superconductivity, which would earn him a second Nobel Prize in 1972.
Walter Brattain moved to another part of Bell Labs.
William Shockley decided to stick with the transistor, eventually
forming his own corporation to develop it further. His decision would
have extraordinary consequences for the computer industry. With a small
amount of capital, Shockley set about hiring the best brains he could
find in American universities, including young electrical engineer
Robert Noyce (1927–1990) and
research chemist Gordon Moore (1929–).
It wasn't long before Shockley's idiosyncratic and bullying management
style upset his workers. In 1956, eight of them—including Noyce and
Moore—left Shockley Transistor to found a company of their own,
Fairchild Semiconductor, just down the road. Thus began the growth of
"Silicon Valley," the part of California centered on Palo Alto, where
many of the world's leading computer and electronics companies have
been based ever since.
It was in Fairchild's California building that the next breakthrough
occurred—although, somewhat curiously, it also happened at exactly the
same time in the Dallas laboratories of Texas Instruments. In Dallas, a
young engineer from Kansas named Jack Kilby
(1923–2005) was considering how to improve the transistor. Although
transistors were a great advance on vacuum tubes, one key problem
remained. Machines that used thousands of transistors still had to be
hand wired to connect all these components together. That process was
laborious, costly, and error prone. Wouldn't it be better, Kilby
reflected, if many transistors could be made in a single package? This
prompted him to invent the "monolithic" integrated circuit (IC), a
collection of transistors and other components that could be
manufactured all at once, in a block, on the surface of a
semiconductor. Kilby's invention was another step forward, but it also
had a drawback: the components in his integrated circuit still had to
be connected by hand. While Kilby was making his breakthrough in
Dallas, unknown to him, Robert Noyce was perfecting almost exactly the
same idea at Fairchild in California. Noyce went one better, however:
he found a way to include the connections between components in an
integrated circuit, thus automating the entire process.
Photo: An integrated circuit from the 1980s. This is an EPROM
chip (effectively a forerunner of flash memory, which you could only erase with a blast of ultraviolet light).
Mainframes, minis, and micros
The arrival of the UNIVAC-1 had demonstrated big potential for using big "number-crunching" computers in big business applications, even though only a dozen were sold. In the early 1950s, IBM tested the
value of this new business model by developing the 701, its first successful "mainframe"
(large, general-purpose computer), built out of vacuum tubes. Almost two dozen of the machines
were delivered, mostly to scientific and military users in the United States, who leased them for around $15,000 per month.
Photo: An IBM 704 mainframe pictured at NASA in 1958. Designed by Gene Amdahl, this scientific number cruncher was the successor to the 701 and helped pave the way to arguably the most important IBM computer of all time, the System/360, which Amdahl also designed. Photo courtesy of
But it was in business where computing would really make its mark.
During the 1960s, commercial computing entered a truly "virtuous circle."
As IBM (which controlled two thirds of the market) and the
so-called "seven dwarfs" (its smaller rivals—Sperry Rand,
Control Data Corporation, Honeywell, Burroughs, General Electric, RCA, and NCR)
developed increasingly powerful mainframes, businesses found ways to gain commercial advantages
by deploying them. The more machines the computer makers leased or sold,
the more revenue they generated, and the more they could invest in developing
even better machines and technologies (like faster and smaller circuits and chips, improved memories, and better peripherals, such as printers and disk drives). This, in turn, opened up bigger markets, pulled in more customers, and generated even more revenue.
It was a truly golden age and nothing represented it better than IBM's classic System/360 mainframe,
a general-purpose computer, built out of transistors and integrated circuits, with a
wide range of add-on equipment that could be all things to all users (hence the
name: 360 covering "360 degrees"—literally, every possible use).
Thanks to miniaturization, mainframes started shrinking into
much smaller, much more affordable machines nicknamed minicomputers,
typified by the classic Digital Equipment Corporation (DEC) PDP-8,
introduced in 1965. A later model, the PDP-10, popularized a concept called
time-sharing, which allowed multiple users to run their own
programs on the same machine at the same time—and, if it ran fast
enough, you could even pretend you had your own machine.
Photo: The control panel of DEC's classic 1965 PDP-8 minicomputer.
Photo by Cory Doctorow published on
Flickr in 2020 under a Creative Commons (CC BY-SA 2.0) licence.
Integrated circuits, as much as transistors, helped to shrink
computers during the 1960s. In 1943, IBM boss Thomas Watson had
reputedly quipped: "I think there is a world market for about five
computers." Just two decades later, the company and its competitors had
installed around 25,000 large computer systems across the United
States. As the 1960s wore on, integrated circuits became increasingly
sophisticated and compact. Soon, engineers were speaking of large-scale
integration (LSI), in which hundreds of components could be crammed
onto a single chip, and then very large-scale integrated (VLSI), when
the same chip could contain thousands of components.
The logical conclusion of all this miniaturization was that,
someday, someone would be able to squeeze an entire computer onto a
chip. In 1968, Robert Noyce and Gordon Moore had left Fairchild to
establish a new company of their own. With integration very much in
their minds, they called it Integrated Electronics or Intel for short.
Originally they had planned to make memory chips, but when the company
landed an order to make chips for a range of pocket calculators,
history headed in a different direction. A couple of their engineers,
Federico Faggin (1941–) and
Marcian Edward (Ted) Hoff (1937–), realized that
instead of making a range of specialist chips for a range of
calculators, they could make a universal chip that could be programmed to work in
them all. Thus was born the general-purpose, single chip computer or
microprocessor—and that brought about the next phase of the computer
By 1974, Intel had launched a popular microprocessor known as the
8080 and computer hobbyists were soon building home computers around it.
The first was the MITS Altair 8800, built by Ed
Roberts. With its front panel covered in red
LED lights and
toggle switches, it was a far cry from modern PCs and laptops. Even so,
it sold by the thousand and earned Roberts a fortune. The Altair
inspired a Californian electronics wizard name Steve
Wozniak (1950–) to develop a computer of his own. "Woz" is often
described as the hacker's "hacker"—a technically brilliant and highly
creative engineer who pushed the boundaries of computing largely for
his own amusement. In the mid-1970s, he was working at the
Hewlett-Packard computer company in California, and spending his free
time tinkering away as a member of the Homebrew Computer Club in the
After seeing the Altair, Woz used a 6502 microprocessor (made by an
Intel rival, Mos Technology) to build a better home computer of his
own: the Apple I. When he showed off his machine to his colleagues at
the club, they all wanted one too. One of his friends, Steve Jobs (1955–2011), persuaded Woz that they should
go into business making the machine. Woz agreed so, famously, they set
up Apple Computer Corporation in a garage belonging to Jobs' parents.
After selling 175 of the Apple I for the devilish price of $666.66, Woz
built a much better machine called the Apple ][ (pronounced "Apple
Two"). While the Altair 8800 looked like something out of a science
lab, and the Apple I was little more than a bare circuit board, the
Apple ][ took its inspiration from such things as Sony televisions and
stereos: it had a neat and friendly looking cream plastic case.
Launched in April 1977, it was the world's first
easy-to-use home "microcomputer." Soon home users, schools, and small
businesses were buying the machine in their tens of thousands—at $1298
a time. Two things turned the Apple ][ into a really credible machine
for small firms: a disk drive unit, launched in 1978, which made it
easy to store data; and a spreadsheet program called VisiCalc, which
gave Apple users the ability to analyze that data. In just two and a
half years, Apple sold around 50,000 of the machine, quickly
accelerating out of Jobs' garage to become one of the world's biggest
companies. Dozens of other microcomputers were launched around this
time, including the TRS-80 from Radio Shack (Tandy in the UK) and the
Photo: Microcomputers—the first PCs. The Apple ][ was one of the first truly popular home computers, designed with user-friendliness in mind. Apple ][ photo by
Creative Commons (CC BY-SA 2.0 FR) licence.
Apple's success selling to businesses came as a great shock to IBM
and the other big companies that dominated the computer industry. It
didn't take a VisiCalc spreadsheet to figure out that, if the trend
continued, upstarts like Apple would undermine IBM's immensely lucrative
business market selling "Big Blue" computers. In 1980, IBM finally
realized it had to do something and launched a highly streamlined
project to save its business. One year later, it released the IBM
Personal Computer (PC), based on an Intel 8080 microprocessor, which
rapidly reversed the company's fortunes and stole the market back from
The PC was successful essentially for one reason. All the dozens of
microcomputers that had been launched in the 1970s—including the Apple
][—were incompatible. All used different hardware and worked in
different ways. Most were programmed using a simple, English-like
language called BASIC, but each one used its own flavor of BASIC, which
was tied closely to the machine's hardware design. As a result,
programs written for one machine would generally not run on another one
without a great deal of conversion. Companies who wrote software
professionally typically wrote it just for one machine and,
consequently, there was no software industry to speak of.
In 1976, Gary Kildall (1942–1994), a
teacher and computer scientist, and one of the founders of the Homebrew
Computer Club, had figured out a solution to this problem. Kildall
wrote an operating system (a computer's fundamental control software)
called CP/M that acted as an intermediary between the user's programs
and the machine's hardware. With a stroke of genius, Kildall realized
that all he had to do was rewrite CP/M so it worked on each different
machine. Then all those machines could run identical user
programs—without any modification at all—inside CP/M. That would make
all the different microcomputers compatible at a stroke. By the early
1980s, Kildall had become a multimillionaire through the success of his
invention: the first personal computer operating system. Naturally,
when IBM was developing its personal computer, it
approached him hoping to put CP/M on its own machine. Legend has it
that Kildall was out flying his personal plane when IBM called, so
missed out on one of the world's greatest deals. But the truth seems to
have been that IBM wanted to buy CP/M outright for just $200,000, while
Kildall recognized his product was worth millions more and refused to
sell. Instead, IBM turned to a young programmer named Bill Gates (1955–).
His then tiny company, Microsoft, rapidly put together an operating system called DOS,
based on a product called QDOS (Quick and Dirty Operating System), which they acquired
from Seattle Computer Products. Some believe Microsoft and IBM cheated Kildall
out of his place in computer history; Kildall himself accused them of copying his ideas.
Others think Gates was simply the shrewder businessman. Either way, the IBM PC, powered by Microsoft's operating system,
was a runaway success.
Yet IBM's victory was short-lived. Cannily, Bill Gates had sold IBM the
rights to one flavor of DOS (PC-DOS) and retained the rights to a very
similar version (MS-DOS) for his own use. When other computer
manufacturers, notably Compaq and Dell, starting making IBM-compatible
(or "cloned") hardware, they too came to Gates for the software. IBM
charged a premium for machines that carried its badge, but consumers
soon realized that PCs were commodities: they contained almost
identical components—an Intel microprocessor, for example—no matter
whose name they had on the case. As IBM lost market share, the ultimate
victors were Microsoft and Intel, who were soon supplying the software
and hardware for almost every PC on the planet. Apple, IBM, and Kildall
made a great deal of money—but all failed to capitalize decisively on
their early success.
Photo: Personal computers threatened companies making
large "mainframes" like this one.
Picture courtesy of NASA on the Commons
(where you can download a larger version).
The user revolution
Fortunately for Apple, it had another great idea. One of the Apple
II's strongest suits was its sheer "user-friendliness." For Steve Jobs,
developing truly easy-to-use computers became a personal mission in the
early 1980s. What truly inspired him was a visit to PARC (Palo Alto
Research Center), a cutting-edge computer laboratory then run as a
division of the Xerox Corporation. Xerox had started developing
computers in the early 1970s, believing they would make paper
(and the highly lucrative photocopiers Xerox made) obsolete. One of PARC's
research projects was an advanced $40,000 computer called the Xerox
Alto. Unlike most microcomputers launched in the 1970s, which were
programmed by typing in text commands, the Alto had a desktop-like
screen with little picture icons that could be moved around with a mouse: it was
the very first graphical user interface (GUI, pronounced "gooey")—an
idea conceived by
Alan Kay (1940–) and now used in virtually
every modern computer. The Alto borrowed some of its ideas, including
the mouse, from 1960s computer
pioneer Douglas Engelbart (1925–2013).
Photo: During the 1980s, computers started to converge
on the same basic "look and feel," largely inspired by the work of pioneers
like Alan Kay and Douglas Engelbart.
Photographs in the Carol M. Highsmith Archive, courtesy of
US Library of Congress, Prints and Photographs Division.
Back at Apple, Jobs launched his own version of the Alto project to
develop an easy-to-use computer called PITS (Person In The Street).
This machine became the Apple Lisa, launched in January 1983—the first
widely available computer with a GUI desktop. With a retail price of
$10,000, over three times the cost of an IBM PC, the Lisa was a
commercial flop. But it paved the way for a better, cheaper machine
called the Macintosh that Jobs unveiled a year later, in January 1984.
With its memorable launch ad for the Macintosh inspired by George Orwell's novel 1984,
and directed by Ridley Scott (director of the dystopic movie Blade Runner),
Apple took a swipe at IBM's monopoly, criticizing what it portrayed as
the firm's domineering—even totalitarian—approach: Big Blue was really
Big Brother. Apple's ad promised a very different vision: "On January 24, Apple Computer will introduce Macintosh. And you'll see why 1984 won't be like '1984'."
The Macintosh was a critical success and helped to invent
the new field of desktop publishing in the mid-1980s, yet it never came
close to challenging IBM's position.
Ironically, Jobs' easy-to-use machine also helped Microsoft to
dislodge IBM as the world's leading force in computing. When Bill Gates
saw how the Macintosh worked, with its easy-to-use picture-icon
desktop, he launched Windows, an upgraded version of his MS-DOS
software. Apple saw this as blatant plagiarism and filed a $5.5 billion
copyright lawsuit in 1988. Four years later, the case collapsed with
Microsoft effectively securing the right to use the Macintosh "look and
feel" in all present and future versions of Windows. Microsoft's
Windows 95 system, launched three years later, had an easy-to-use,
Macintosh-like desktop and MS-DOS running behind the scenes.
Photo: The IBM Blue Gene/P supercomputer at
Argonne National Laboratory: one of the world's most powerful
computers. Picture courtesy of Argonne National Laboratory published on
Wikimedia Commons in 2009 under a Creative Commons Licence.
From nets to the Internet
Standardized PCs running standardized software brought a big benefit
for businesses: computers could be linked together into networks to
share information. At Xerox PARC in 1973, electrical engineer Bob Metcalfe (1946–) developed a new way of
linking computers "through the ether" (empty space) that he called
Ethernet. A few years later, Metcalfe left Xerox to form his own
company, 3Com, to help companies realize "Metcalfe's Law": computers
become useful the more closely connected they are to other people's
computers. As more and more companies explored the power of local area
networks (LANs), so, as the 1980s progressed, it became clear that
there were great benefits to be gained by connecting computers over
even greater distances—into so-called wide area networks (WANs).
Photo: Computers aren't what they used to be: they're much less noticeable because they're much more seamlessly integrated into everyday life. Some are "embedded" into household gadgets like coffee makers or televisions. Others travel round in our pockets in our smartphones—essentially pocket computers that we can program simply by downloading "apps" (applications).
Today, the best known WAN is the Internet—a
global network of individual computers and LANs that links up hundreds
of millions of people. The history of the Internet is another story,
but it began in the 1960s when four American universities launched a
project to connect their computer systems together to make the first
WAN. Later, with funding for the Department of Defense, that network
became a bigger project called ARPANET (Advanced Research Projects
Agency Network). In the mid-1980s, the US National Science Foundation
(NSF) launched its own WAN called NSFNET. The convergence of all these
networks produced what we now call the Internet later in the 1980s.
Shortly afterward, the power of networking gave British computer
programmer Tim Berners-Lee (1955–) his big
idea: to combine the power of computer networks with the
information-sharing idea Vannevar Bush had proposed in 1945. Thus, was
born the World Wide Web—an easy way
of sharing information over a computer network, which made possible
the modern age of cloud computing
(where anyone can access vast computing power over the Internet without having to worry
about where or how their data is processed).
It's Tim Berners-Lee's invention that brings you this potted history of computing today!
And now where?
What of the future? The power of computers (the number of components packed on a chip) has doubled
roughly every 18 months to 2 years since the 1960s. But the laws of physics are expected to bring
a halt to Moore's Law, as this idea is known, and force us to explore
entirely new ways of building computers. What will tomorrow's PCs look like? One long-touted idea is that they'll be using particles of light—photons—instead of electrons, an approach known as optical computing or photonics. Currently,
much of the smart money is betting on quantum computers, which deploy cunning ways of
manipulating atoms to process and store information at lightning speed.
There's also hope we might use
(harnessing the "spin" of particles) and
biomolecular technology (computing with DNA, proteins, and other biological molecules), though both are in the very
early stages of research.
Chips made from new materials such as graphene may also offer ways of
extending Moore's law. Whichever technology wins out, you can be quite certain the future of computing will
be just as exciting as the past!