In 1902, a young electrical engineer called Frank Pearne approached Mr. Joy Morton, the president of the well-known
Morton Salt Company. Pearne had been experimenting with printing telegraphs and needed a sponsor. Morton
discussed the situation with his friend, the distinguished mechanical engineer Charles L. Krum, and they eventually
decided they were interested in pursuing this project.
After a year of unsuccessful experiments, Pearne lost interest and wandered off into the sunset to become a teacher.
Krum continued to investigate the problem and, in 1906, was joined by his son Howard, who had recently graduated
as an electrical engineer. The mechanical and electrical talents of the Krums Senior and Junior complemented each other.
After solving the problem of synchronizing the transmitter and receiver, they oversaw their first installation on postal
lines between New York City and Boston in the summer of 1910.
These devices, called teleprinters, had a typewriter-style keyboard for entering outgoing messages and a roll of
paper for printing incoming messages. The Krums continued to improve the reliability of their systems over the years.
By 1914, teleprinters were being used by the Associated Press to deliver copy to newspaper offices throughout
America, and by the early 1920s they were in general use around the world.
Meanwhile, toward the end of the 1920s and the early 1930s, scientists and engineers began to focus their attentions
on the issue of computing. The first devices, such as Vannevar Bush's Differential Analyzer, were predominantly analog,
but not everyone was a devotee of analog computing.
1906 The vacuum Tube
Edison did not develop his light bulb vacuum tube findings any further, but an English physicist, John Ambrose Fleming,
discovered that the Edison Effect could also be used to detect radio waves and to convert them to electricity.
Fleming went on to develop a two-element vacuum tube known as diode
In 1906, the American inventor Lee de Forest introduced a third electrode called the grid into the vacuum tube.
The resulting triode could be used as both an amplifier and a switch, and many of the early radio transmitters
were built by de Forest using these triodes (he also presented the first live opera broadcast and the first news
report on radio).
De Forest's triodes revolutionized the field of broadcasting and were destined to do much more, because
their ability to act as switches was to have a tremendous impact on digital computing.
1918 The Enigma machine
Enigma was an electro-mechanical device that utilised a series of three (and then four) stepping wheels
in a system to 'scramble' a plain text message to produce cipher text via polyalphabetic substitution.
The number of cipher text alphabets is enormous, leading Germany's military authorities to believe,
wrongly as it turned out, in the absolute security of this cipher system.
Although this machine had been available since the 1918, and exhibited in 1920, it was only seen as a
usable coding machine by the Polish and German armies.
At this exhibition the British secret service
also purchased an Enigma machine to evaluate but thought it too complicated. This machine lay undetected
in a basement at MI5 HQ all through the Second World War. Had it been found many more lives may have
been saved through its use. A good source of information can
be found here>>
John Logie Baird in England and Clarence Hansell in the US patent the idea of using
ARRAYS of hollow pipes or transparent rods to transmit images - basic fibre
1926 The Transistor Pt1
The transistor and subsequently the integrated circuit must certainly qualify as two of the greatest inventions
of the twentieth century. These devices are formed from materials known as semiconductors, whose properties
were not well-understood until the 1950s. However, as far back as 1926, Dr. Julius Edgar Lilienfield from New York
filed for a patent on what we would now recognize as an NPN junction transistor being used in the role of an
amplifier (the patent title was "Method and apparatus for controlling electric currents"
1931 The electric logic machine
In 1936, the American psychologist Benjamin Burack from Chicago constructed what was probably the
world's first electrical logic machine. Burack's device used light bulbs to display the logical relationships
between a collection of switches, but for some reason he didn't publish anything about his work until 1949.
1937 First electric computer
John Vincent Atanasoff conceived basic design principles for the first electronic-digital computer in
the winter of 1937 and, assisted by his graduate student, Clifford E. Berry, constructed a prototype
in October 1939. It used binary numbers, direct logic for calculation, and
a regenerative memory. It embodied concepts that would be central to the future
development of computers.
They created the first computing machine to use electricity, vacuum tubes,
binary numbers and capacitors. The capacitors were in a rotating drum that held
the electrical charge for the memory. Berry, with his background in electronics
and mechanical construction skills, was the ideal partner for Atanasoff.
prototype won the team a grant of $850 to build a full-scale model. They spent
the next two years further improving the Atanasoff-Berry Computer (aka ABC). The
final product was the size of a desk, weighed 700 pounds, had over 300 vacuum
tubes, and contained a mile of wire. It could calculate about one operation
every 15 seconds, today a computer can calculate 150 billion operations in 15
seconds. Too large to go anywhere, it remained in the basement of the physics
department. The war effort prevented Atanasoff from finishing the patent process
and doing any further work on the computer. When they needed storage space in
the physics building, they dismantled the Atanasoff-Berry Computer.
1937 Turing Machine
The need to solve the complicated codes used by Germany in their build up to
war brought a requirement for some sort of machine to solve the huge amount
of variations machines like Enigma could produce.
In 1937, while a graduate student, Alan Turing wrote a paper amusingly entitled On Computable Numbers
with an Application to the Entscheidungsproblem. The premise of Turing's paper was that some classes
of mathematical problems don't lend themselves to algorithmic representations and so aren't easily
solved by machines.
Since Turing didn't have access to a real computer, because they didn't exist at
the time, he invented his own as an abstract 'paper exercise', which consisted of a grid of squares,
each containing a zero or a one. This theoretical model became known as a Turing Machine, and is one
of the first descriptions of a software program working with probabilities in a binary computing environment.
The War Department brought him and many of his university colleagues and ex
university tutors together to work on the problem of breaking the
German codes. They were housed in a large country house in Bletchley Park, Buckinghamshire called
"station X". Here Turing and his team cracked the
codes and then built Colossus
with the help and expertise of Tom Flowers to crack the more complicated
The Second World War really accelerated the inventions required
for the war effort. One of these inventions was Turin's computer. Sadly in the
1950's Alan Turing was convicted of homosexuality and committed suicide in
1954. This was a tragic end to such an influential figure in the world of
1937 Zuse's Z1
Zuse's Z1 The first known working binary digital computer was called the ZI and was built by Konrad
Zuse. It had a mechanical memory system.
A prototype with electromagnetic relays called the Z2 was built a year later, with storage capacity
for 16 words, plus card punch and reader 1/0. It had 200 relays and operated with 16-bit integer
arithmetic. The idea was to use this basic design in a bigger system like the ZI. The result was the Z3,
which had a 64-word capacity, floating point arithmetic,22-bit word length and 2,400 relays.
Of these, 600 were for calculations and 1,800 for memory. Although based on relays, the Z3 was very sophisticated
for its time; for example, it utilized the binary number system and could handle floating-point arithmetic.
(Zuse had considered employing vacuum tubes, but he decided to use relays because they were more readily
available, and also because he feared that tubes were somewhat unreliable).
Construction was interrupted in 1939 when Zuse was called up for military service, so the, Z3 wasn't
completed until 1941. The Z3 was the first fully functioning, program-controlled electromechanical
The first three Z computers were destroyed during the war (although a new Z3 was reconstructed in the
1960s). Zuse started work on a general-purpose relay computer called the Z4. this did survive the bombing
(in a cave in the Bavarian Alps) and by 1950 it was up and running in a Zurich bank. The Z4 was started in 1942
and was intended to have a storage capacity of 1,024 words.
It is interesting to note that paper was in short supply in Germany during to the war, so instead of using
paper tape or punched cards, Zuse was obliged to punch holes in old movie film to store his programs and data.
We may only speculate as to the films Zuse used for his hole-punching activities; for example, were any first-edition
Marlene Dietrich classics on the list? (Marlene Dietrich fell out of favor with the Hitler regime when she emigrated to
America in the early 1930s, but copies of her films would still have been around during the war.)
Zuse was an amazing man, who, in many respects, was well ahead of his time. For example, in 1958 he proposed a
parallel processor called a field computer, years before parallel computing became well understood. He also wrote
(but never implemented) Pkankalkül, which is a strong contender as the first high-level programming language.
To fully appreciate Zuse's achievements, it is necessary to understand that his background was in construction engineering.
Also, Zuse was completely unaware of any computer-related developments in Germany or in other countries until a very late
stage. In 1957, Zuse received the honorary degree of Dr.techn. in Berlin, and he was subsequently showered with many
other honors and awards. There is an excellent
a biography and an image gallery of the various machines.
1940 Claud Shannon
The connection between Boolean algebra and circuits based on switches had been recognized as early as 1886
by an educator called Charles Pierce, but nothing substantial happened in this area until Claude E. Shannon published
his 1938 paper.
Following Shannon's paper, a substantial amount of attention was focused on developing electronic logic machines.
Unfortunately, interest in special-purpose logic machines waned in the 1940s with the advent of general-purpose
computers, which proved to be much more powerful and for which programs could be written to handle formal logic.
Teleprinters to modems
At a meeting in New Hampshire in September 1940 George Robert Stibitz used a digital machine to perform the
first demonstration of remote computing. Leaving his computer in New York City, he took a teleprinter to the
meeting which he connected to the computer using a telephone line. Stibitz then proceeded to astound the
attendees by allowing them to pose problems which were entered on the teleprinter; within a minute,
the teleprinter printed the answers generated by the computer.
1941 Tom Flowers
The design for the theoretical Turing Machine (later Colossus) was invented
and built by a post office engineer called Tom Flowers.
Flowers was a Londoner with a passion for electronics. Having gained his degree in electronic engineering he went to work for
the Post Office. His dream was to try to convert Britain's mechanical telephone system into an electronic one,
but opinion was against him. During the Second World War he was drafted into Bletchley Park to join the ranks of
mathematicians and cryptographers who were trying to crack Germany's code system.
When he saw the project for Turing's machine from Professor Max
Newman (one of Turing's old tutors at Cambridge) he felt that the overall
machine was similar to an automatic telephone exchange system.
now became an urgency for a machine powerful enough to break the Lorenz code created by the
German Geheimfernschreiber (secret telegraph), which was far stronger than
ENIGMA and indeed was the code used by Adolph Hitler himself for his
Tom Flowers felt that
what was needed for this machine was a massive collection of switches just
like his ideas for the new automatic telephone exchange. The
current problem of running two teleprinter tapes in line fully synchronised with
each other had not been solved. The tapes kept running out of step with each
other. What was needed was a faster system that memorised one side of the
stream making side by side synchronising a thing of the past.
To do this
he was to use
over 1800 valves instead of mechanical switches. Valves were not seen to be
reliable enough however Flowers suggested that valves were fine if never
switched off and had proved this with the post office exchanges.
Due to the
war offices belief in the unreliability of valves and the time it would take to build they dismissed the idea.
however to build one himself using at the
GPO research facility at Dolly's hill. Using his own money and working around the clock he
designed and built it in only 10 months. This machine was called Colossus
(because it was colossal filling a whole room). The Colossus Mark I was one of the world's earliest
(if not the first) working programmable electronic digital computer and could crack the most
comprehensive German code within hours giving the allies a huge advantage.
The war office immediately ordered 10 machines even after their initial
After the war Tommy returned to the GPO and tried to convince
his superiors of the use of computers. The were unaware that he had built
one already because of the official secrets act. They were unconvinced and
Britain again lost out to the Americans on the computer revolution.
Without doubt it was Tommy Flowers who turned the genius of Alan Turin's ideas into a real working computer that turned the
tide of world events at the time and started the revolution of the electronic computer. Tommy
Flowers died on 28 October 1998, aged 92.
The Colossus Mark I consisted of 1,800 vacuum tubes
(valves), and was soon
superseded by (and upgraded to) the Mark 2. Due to the 1800 valves
Colossus was huge and filled a whole room. It could read data at 5,000
characters per second and could perform up to 100 Boolean operations simultaneously
through each of its five tape channels across a five-character matrix, in 200 microseconds.
Although it's hard to equate this with today's calculating power, Colossus' extreme specialisation makes it fast at breaking codes even compared to today's computers.
It was calculated that the war was shortened by a whole year and countless
lives saved. In D-Day alone the awareness of two Panzer divisions on a
proposed landing site saved many lives. At the end of the war all but two of
the Colossus machines (they were used by GCHQ to spy on de-code Russian information
and at least one may still be intact) were dismantled however
In 1996, a Colossus was rebuild and went on show at Bletchley Park museum.
Considered by some to be the first electronic digital computer, this massive American machine with
18,000 tubes was predated by both Colossus and Konrad Zuse's first four Z systems.
The American military were pushing for a machine that would calculate
ballistics and therefore were providing substantial funding.
ENIAC was the prototype from which most other modern computers evolved. It embodied almost all the components
and concepts of today's high- speed, electronic digital computers. Its designers conceived what
has now become standard circuitry such as the gate (logical "and" element), buffer
(logical "or" element) and used a modified Eccles-Jordan flip-flop as a logical, high-speed
storage-and-control device. The machine's counters and accumulators, with more sophisticated
innovations, were made up of combinations of these basic elements.
ENIAC could discriminate the sign of a number, compare quantities for equality, add, subtract,
multiply, divide, and extract square roots. ENIAC stored a maximum of twenty 10-digit decimal numbers.
Its accumulators combined the functions of an adding machine and storage unit. No central memory unit
existed, per se. Storage was localized within the functioning units of the computer.
The primary aim of the designers was to achieve speed by making ENIAC as all-electronic as possible.
The only mechanical elements in the final product were actually external to the calculator itself.
These were an IBM card reader for input, a card punch for output, and the 1,500 associated relays.
More information can be
Cybernetics is the fancy name for systems theory, which studies the way feedback loops work. It was invented
during the 1940s at the Massachusetts Institute of Technology and paved the way for automation and computing.
A multidisciplinary team including Norbert Wiener (mathematician), Warren McCulloch (neurophysiologist) and
Jay Forrester (electronics engineer) modelled theories of how living organisms worked on self-regulating mechanical
processes, and vice versa. Wiener's Cybernetics, or Control and Communication in the Animal and the Machine, and The
Mathematical Theory of Communication by Claude Shannon and Warren Weaver, both published in 1948, marked the arrival
of a new epoch. The latter founded info!mation theory.
In 1948 The Transistor Pt22
Bell Laboratories in the United States began research into semiconductors in 1945, and physicists William Shockley,
Walter Brattain and John Bardeen succeeded in creating the first point- contact germanium transistor on the 23rd
December, 1947 (they took a break for the Christmas holidays before publishing their achievement, which is why
some reference books state that the first transistor was created in 1948).
Maurice Wilkes assembled the EDSAC, the first practical stored-program computer,
at Cambridge University. His ideas grew out of the Moore School lectures he had
attended three years earlier. EDSAC contained 3,000 vacuum tubes and used mercury
delay lines for memory.
For programming the EDSAC, Wilkes established a library of short programs called subroutines
stored on punched paper tapes. Output results were passed to
a tele-printer. Additionally, EDSAC is credited as using one of the first assemblers called
"Initial Orders," which allowed it to be programmed symbolically instead of using
machine code. An article on Maurice Wilkes reproduced from the
excellent Personal Computer World can be found here>>
1949 Joseph Lyons
start development of "LEO"
In October 1947, the directors of
J. Lyons & Company, a British catering company famous for its teashops but
with strong interests in new office management techniques, decided to take an
active role in promoting the commercial development of computers .
See also this excellent web page on the development of LEO>>
and an excellent
By the late 1950s, bipolar transistors were being manufactured out of silicon rather than
germanium (although germanium had certain electrical advantages, silicon was cheaper
and easier to work with). Bipolar junction transistors are formed from the junction of three
pieces of doped silicon called the collector base, and emitter. The original bipolar transistors
were manufactured using the mesa process, in which a doped piece of silicon called the mesa
(or base) was mounted on top of a larger piece of silicon forming the collector, while the
emitter was created from a smaller piece of silicon embedded in the base.
1950 The first digital modem
Digital modems developed from the need to
transmit data for North American air defence during the 1950s. Modems were used
to communicate data over the public switched telephone network or PSTN. Analogue
telephone circuits can only transmit signals that are within the frequency range
of voice communication. A modem sends and receives data between two computers.
Modem stands for modulate/demodulate.
See also the Modem tutorial for all you need to know about modems here>>.
1951 LEO becomes operational
In 1951 the "LEO I" computer was operational and ran the
orld's first regular routine office computer job.The company LEO Computers Ltd was formed in 1954.
LEO II computers were installed in many British offices, including Ford
Motor Company, British Oxygen Company and the 'clerical factory' of the Ministry
of Pensions at Newcastle. LEO lll computers were installed in Customs &
Excise, Inland Revenue, The Post Office and in Australia, South Africa and
LEO Computers Ltd merged with the computer interests of English Electric in
1963 to form English Electric LEO, and later, English Electric Leo Marconi
(EELM). Subsequent mergers eventually found LEO incorporated into ICL in 1968,
whilst the Bureau operation, based at Hartree House, combined with Barclays to
See also this excellent web page on
the development of LEO>>
and an excellent
1956 IBM RAMAC
The era of magnetic disk storage dawned with IBM's shipment of a 305 RAMAC to Zellerbach
Paper in San Francisco. The IBM 350 disk file served as the storage component for the Random
Access Method of Accounting and Control. It consisted of 50 magnetically coated metal platters
with 5 million bytes of data. The platters, stacked one on top of the other, rotated with a common
1959 The Integrated Circuit
The invention of the IC (Integrated Circuit) was central to the industry as we know it. In the late 1950s,
electrical engineers were confounded by a problem they called the Tyranny of Numbers. This grandiose title
referred to the problem of manufacturing the constituent electrical parts to make increasing complex circuits
from discrete components. The problem was that as the design for circuits improved, the number of components
required grew exponentially, far in excess of the number that could actually be physically assembled together.
The solution to this came from two men. John Kilby was working at Texas Instruments and Robert Noyce at Fairchild
Semiconductors. Their answer was to fabricate complete networks of components on to a single crystal of semiconductor
material. This breakthrough, named the monolithic integrated circuit, enabled devices to be made much smaller, more
complex and considerably faster, and is credited as being the discovery that kicked off the computer revolution of the
late 20th century. In fact, Robert Royce went on to be one of the key instigators of this revolution as co-founder of
chip giant Intel.