cOMPUter HisTory...

"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

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

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

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.

Charles Babbage

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

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