"History oF Computers"
Computing hardware has
been an essential component of the process of calculation and data storage
since it became useful for numerical values to be processed and shared.
The
earliest computing hardware was probably some form of tally
stick; later recording devices include the Phoenician clay shapes which
represented counts of items, probably livestock or grains, in containers. These
seem to have been used by the merchants, accountants, and government officials
of the time.
Devices to aid computation have evolved from simple recording and counting devices through the abacus, the slide rule, and more recent electronic computers. Even today, an experienced abacus user using a device designed hundreds of years ago can sometimes complete basic calculations more quickly than an unskilled person using an electronic calculator - though for more complex calculations, computers out-perform even the most skilled human.
This
article presents the major developments in the history of computing hardware
and attempts to put them in context.
Earliest devices
Humanity has used devices to aid in computation for millennia.
Chinese and others frustrated with
counting on their fingers invented the Abacus
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One example is a device for establishing equality by weight: the
classic scales, later used to symbolize equality in justice. Another is simple
enumeration: the checkered cloths of the counting houses served as simple data
structures for enumerating stacks of coins, by weight. A more
arithmetic-oriented machine is the abacus. One of the earliest machines
of this type was the
Chinese abacus.
First mechanical calculators
In 1623 Wilhelm Schickard built the first mechanical calculator
and thus became the father of the computing era.
Gears are at the heart of mechanical
devices like the Curta calculator
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Since his machine used techniques such as cogs and gears first
developed for clocks, it was also called a 'calculating clock'. It was put to
practical use by his friend Johannes Kepler, who revolutionized astronomy.
Machines by Blaise Pascal (the Pascaline, 1642) and Gottfried
Wilhelm von Leibniz (1671) followed. Around 1820, Charles Xavier Thomas created
the first successful, mass-produced mechanical calculator, the Thomas
Arithmometer, that could add, subtract, multiply, and divide. It was mainly
based on Leibniz's work. Mechanical calculators, like the base-ten addiator,
the comptometer, the Monroe, the Curta and the Addo-X remained in use until the
1970s.
1801: punched card technology
In 1801, Joseph-Marie Jacquard developed a loom in which the
pattern being woven was controlled by punched cards. The series of cards could
be changed without changing the mechanical design of the loom. This was a
landmark point in programmability.
The slide rule, a basic mechanical
calculator, facilitates multiplication and division
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In 1833, Charles Babbage moved on from developing his difference
engine to developing a more complete design, the analytical engine which would
draw directly on Jacquard's punch cards for its programming.
Herman
Hollerith invented a tabulating machine using punch cards in the 1880s.
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Charles Babbage
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1835-1900s:
first programmable machines
The defining feature of a "universal computer" is
programmability, which allows the computer to emulate any other calculating
machine by changing a stored sequence of instructions.
In 1835 Charles Babbage described his analytical engine. It was
the plan of a general-purpose programmable computer, employing punch cards for
input and a steam engine for power. One crucial invention was to use gears for
the function served by the beads of an abacus. In a real sense, computers all
contain automatic abacuses (technically called the ALU or floating-point unit).
Augusta
Ada King, Countess of Lovelace
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1930s-1960s: desktop calculators
In 1948, the Curta was introduced. This was a small, portable, mechanical
calculator that was about the size of a pepper grinder. Over time, during the
1950s and 1960s a variety of different brands of mechanical calculator appeared
on the market.
The first desktop electronic calculator was probably Sumlock
Comptometer's 1961 Anita C/VIII, which used a Nixie tube display and 177
subminiature thyratron tubes. In June 1963, Friden introduced the four-function
EC-130. It had an all-transistor design, 13-digit capacity on a 5-inch CRT, and
introduced reverse Polish notation (RPN) to the calculator market at a price of
$2200. The model EC-132 added square root and reciprocal functions. In 1965,
Wang Laboratories produced the LOCI-2, a 10-digit transistorized desktop
calculator that used a Nixie tube display and could compute logarithms.
Pre-1940 analog computers
Since computers were rare in this era, the solutions were often
hard-coded into paper forms such as graphs and nomograms, which could then
allow analog solutions to problems, such as the distribution of pressures and
temperatures in a heating system.
Some of the most widely deployed analog computers included devices
for aiming weapons, such as the Norden bombsight and artillery aiming computers
for battleships. Some of these stayed in use for decades after WWII.
Hybrid analog computers, controlled by digital electronics,
remained in substantial use into the 1950s and 1960s, and later in some
specialised applications.
1940s: first
electrical digital computers
The era of modern computing began with a flurry of development
before and during World War II, as electronic circuits, relays, capacitors and
vacuum tubes replaced mechanical equivalents and digital calculations replaced
analog calculations. The computers designed and constructed then have sometimes
been called 'first generation' computers. First generation computers such as
the Atanasoff-Berry Computer, Z3 and Colossus were built by hand using circuits
containing relays or vacuum valves (tubes), and often used punched cards or
punched paper tape for input and as the main (non-volatile) storage medium.
Temporary, or working storage, was provided by acoustic delay lines (which use
the propagation time of sound in a medium such as wire to store data) or by
Williams tubes (which use the ability of a television picture tube to store and
retrieve data). By 1954, magnetic core memory was rapidly displacing most other
forms of temporary storage, and dominated the field through the mid-1970s.
American developments
In 1937, Claude Shannon
produced his master's thesis at MIT that implemented Boolean algebra using
electronic relays and switches for the first time in history. Entitled A
Symbolic Analysis of Relay and Switching Circuits, Shannon's thesis essentially
founded practical digital circuit design.
In November of 1937, George Stibitz, then working at Bell Labs,
completed a relay-based computer he dubbed the "Model K" (for
"kitchen", where he had assembled it), which calculated using binary
addition. Bell Labs thus authorized a full research program in late 1938 with
Stibitz at the helm. Their Complex Number Calculator, completed January 8,
1940, was able to calculate complex numbers. In a demonstration to the American
Mathematical Society conference at Dartmouth College on September 11, 1940,
Stibitz was able to send the Complex Number Calculator remote commands over
telephone lines by a teletype. It was the first computing machine ever used
remotely over a phone line. Some participants of the conference who witnessed
the demonstration were John Von Neumann, John Mauchly, and Norbert Wiener, who
wrote about it in his memoirs.
Colossus
was used to break German ciphers during World War II
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