# COMPUTER SCIENCE 2500a.c.-1942

Timeline created by irene urrutia
• 2,500 BCE

# La tablilla Plimpton - Mesopotamia (Irak)

It shows 60 numbers in 15 rows and 4 columns. It is known to be a piece of a larger splint that had 38 rows and 8 columns. The strongest hypothesis is that it was a school tablet. The Babylonians used school tablets with the statement of a mathematical problem on one side and its solution on the other.
• 2,000 BCE

# Ábaco - Mesopotamia

It is a calculating tool before the adoption of the written Hindu–Arabic numeral system. Although today many use calculators and computers instead of abacuses to calculate, abacuses still remain in common use in some countries, such as to teach arithmetic to children. Some people who are unable to use a calculator because of visual impairment may use an abacus.
• -500 BCE

# Calendario mesoamericano - Precolombia

Mesoamerican calendars are the calendrical systems devised and used by the pre-Columbian cultures of Mesoamerica. Besides keeping time, Mesoamerican calendars were also used in religious observances and social rituals, such as for divination.
• # Huesos de Napier - John Napier

"Napier's bones" is a manually-operated calculating device created by John Napier of Merchiston, Scotland for the calculation of products and quotients of numbers. The method was based on lattice multiplication, and was also called Rabdology. Using the multiplication tables embedded in the rods, multiplication can be reduced to addition operations and division to subtractions.
• # Reloj calculador - Wilhem Schickard

In 1623 Wilhelm Schickard invented an apparatus that allowed to perform arithmetic operations in a completely mechanical way, the Rechenuhr or calculator clock. This calculator used a complex system of rods and gears that mechanized the operations that previously had to be done manually. No original model of this machine has been preserved; Modern replicas (like this one) have been created thanks to the author's designs that have been preserved.
• # Regla de cálculo - Edmund Wingate

The slide rule is a mechanical analog computer. It is used primarily for multiplication and division, and also, for functions such as exponents, roots, logarithms, and trigonometry, but typically, not for addition or subtraction. Though similar in name and appearance to a standard ruler, the slide rule is not meant to be used for measuring length or drawing straight lines.
• # Pascalina - Blaise Pascal

Pascal's calculator (also known as the arithmetic machine or Pascaline) is a mechanical calculator invented by Blaise Pascal in the early 17th century. Pascal was led to develop a calculator by the laborious arithmetical calculations required by his father's work as the supervisor of taxes in Rouen. He designed the machine to add and subtract two numbers directly and to perform multiplication and division through repeated addition or subtraction.
• # Máquina de multiplicar - Sir Samuel Morlan

The apparatus consisted of a series of wheels, each of which represented tens, hundreds, etc. A steel pin moved the dials to perform the calculations. Unlike pascalina, this device had no automatic column advance.
• # La Rueda de Leibniz= 1ª Máquina de cálculos aritméticos

A Leibniz wheel or stepped drum is a cylinder with a set of teeth of incremental lengths which, when coupled to a counting wheel, can be used in the calculating engine of a class of mechanical calculators. Invented by Leibniz in 1673, it was used for three centuries until the advent of the electronic calculator in the mid-1970s.
• # Tarjeta perforada=1ª memoria - Joseph Jacquard

A punched card is a piece of stiff paper that can be used to contain digital data represented by the presence or absence of holes in predefined positions. Digital data can be used for data processing applications or, in earlier examples, used to directly control automated machinery.
• # 1ª Máquina Analítica - Charles Babbage

The Analytical Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.
• # 1ª programadora de la máquina analítica - Ada Lovelace

Ada was the first person in the world to describe a general programming language in interpreting Babbage's ideas even better than himself. In 1843 he published a series of notes on Babbage's analytical machine that he signed only with his initials for fear of being censored for his status as a woman.
• # El álgebra de Boole y la codificación binaria - George Boole

Boolean algebra is the branch of algebra in which the values of the variables are the truth values true and false, usually denoted 1 and 0 respectively. The main operations of Boolean algebra are the conjunction (and) denoted as ∧, the disjunction (or) denoted as ∨, and the negation (not) denoted as ¬. The binary operation is the one that needs two arguments, in fact it is the most generalized form of operation, usually when we refer to operations, we refer to binary operations.
• # 1ª Máquina Tabuladora - Herman Hollerith

The tabulating machine was an electromechanical machine designed to assist in summarizing information stored on punched cards. Invented by Herman Hollerith, the machine was developed to help process data for the 1890 U.S. Census. Later models were widely used for business applications such as accounting and inventory control. It spawned a class of machines, known as unit record equipment, and the data processing industry.
• # 1ª Máquina Algebraica - Leonardo Torres Quevedo

The purpose of the machine was to obtain values ​​of polynomial functions continuously and automatically.As it was an analog machine, the variable can go through any value (not just preset discrete values).Before a polynomial equation, when turning all the wheels representing the unknown, the final result is giving the values ​​of the sum of the variable terms, when this sum coincides with the value of the second member, the wheel of the unknown marks a root.
• # Máquina Enigma - Ejercito alemán

The Enigma machine is an encryption device employed extensively by Nazi Germany during World War II, in all branches of the German military. Enigma has an electromechanical rotor mechanism that scrambles the 26 letters of the alphabet. In typical use, one person enters text on the Enigma's keyboard and another person writes down which of 26 lights above the keyboard lights up at each key press. If plain text is entered, the lit-up letters are the encoded ciphertext.
• # 1er Analizador Diferencial - Vannevar Bush

The differential analyser is a mechanical analogue computer designed to solve differential equations by integration, using wheel-and-disc mechanisms to perform the integration. It was one of the first advanced computing devices to be used operationally. The original machines could not add, but then it was noticed that if the two wheels of a rear differential are turned, the drive shaft will compute the average of the left and right wheels.
• # Máquina Universal de Turing - Alan Turing

A universal Turing machine is a Turing machine that can simulate an arbitrary Turing machine on arbitrary input. The universal machine achieves this by reading both the description of the machine to be simulated as well as the input to that machine from its own tape. Alan Turing introduced the idea of such a machine in 1936–1937. This principle is considered to be the origin of the idea of a stored-program computer used by John von Neumann in 1946 for the "Electronic Computing Instrument".
• # Z1 - Konrad Zuse

The Z1 was a mechanical computer designed by Konrad Zuse from 1936 to 1937 and built by him from 1936 to 1938. It was a binary electrically driven mechanical calculator with limited programmability, reading instructions from punched celluloid film.
• # ABC - John Atanasoff

The Atanasoff–Berry computer (ABC) was the first automatic electronic digital computer. Limited by the technology of the day, and execution, the device has remained somewhat obscure. The ABC's priority is debated among historians of computer technology, because it was neither programmable, nor Turing-complete, unlike the widely famous ENIAC machine of 1947 in part derived from it.
• # Z2 (Konrad Zuse)

The Z2 was a mechanical and relay computer completed by Konrad Zuse in 1940. It was an improvement on the Z1, using the same mechanical memory but replacing the arithmetic and control logic with electrical relay circuits. Photographs and plans for the Z2 were destroyed by the Allied bombing during World War II. In contrast to the Z1, the Z2 used 16-bit fixed-point arithmetic instead of 22-bit floating point.
• # Calculadora de números complejos=CNC - George Robert Stibitz

The machine had the ability to add, subtract, multiply and divide complex numbers - just the kind of problems that are particularly problematic for Bell's engineers.
• # Z3 (Konrad Zuse)

The Z3 was a German electromechanical computer designed by Konrad Zuse. It was the world's first working programmable, fully automatic digital computer. The Z3 was built with 2,600 relays, implementing a 22-bit word length that operated at a clock frequency of about 4–5 Hz. Program code was stored on punched film. Initial values were entered manually.
• # Cibernética - Norbert Wiener

Cybernetics, born from the combination of mathematics and neurophysiology, is proposed as the science that will allow the control of the "antihomeostatic factors" inherent in Nature and the functioning of society. Homeostasis is a central concept of cybernetic theory, and refers to the process by which living organisms retain a certain state of organization within the general tendency of the universe towards corruption and decay, a trend that is known as entropy.
• # Z4 (Konrad Zuse)

The Z4 was the world's first commercial digital computer, designed by German engineer Konrad Zuse and built by his company Zuse Apparatebau in 1945.The Z4 was Zuse's final target for the Z3 design, but like Z2 it was partly mechanical (memory) and electromechanical machine.