HISTORY OF COMPUTERS

Executive Summary concept of computer was 1st time developed in 1623 as introduction of sproceted wheel.after that special gearing system was introduced in 1642 which enable pascle machine for multiplication purpose.the research was continious and was bringing new changes in their shapes. it passes through the following discoveries such as Abacus,Babage’s different Engine,Eniac, Univac…..etc.
In 1930s ibm started work on developing computers and passes throuth the different generation’s of the computers.as the time passes it bacame more user friendly.now computers do every thing we need.it completely changed the life of Human being and made the life more fast and easier. History of Computers
The history of computing began with an analog machine. In 1623 German scientist Wilhelm Schikard invented a machine that used 11 complete and 6 incomplete Sprocketed wheels that could add, and with the aid of logarithm tables, multiply and divide
.French philosopher, mathematician, and physicist Blaise Pascal invented a machine in 1642 that added and subtracted, automatically carrying and borrowing digits from column to column. Pascal built 50 copies of his machine, but most served as curiosities in parlors of the wealthy. Seventeenth-century German mathematician Gottfried Leibniz designed a special gearing system to enable multiplication on Pascal’s machine.
The earliest computers were machines built to make repetitive numerical calculations that had previously been done by hand. By the 1890s calculating machines were used to tabulate the u.s. Census with a punched-card system invented by Herman Hollerith. Electromechanical calculators were being built by the 1930s, especially by a new company called the international business machines company (IBM). The first truly electronic memory and processors were built by john Vincent Atanasoff in 1939 at the Iowa state college, and the first fully functioning electronic computers, a series of ten called colossus, were built by the British secret service during world war ii to help them crack the Germans' secret military codes. The first general-purpose electronic computer in America, called the electronic numerical integrator and computer (Eniac), was introduced at the University of Pennsylvania in 1946. Two of its inventors, American engineers john Presper Eckert, jr., and john Mauchly, moved on to build the first electronic computer for commercial use, the Univac, at the Remington rand corporation.

Abacus The abacus is an instrument used to perform arithmetic calculations. Developed in ancient times, the abacus is still used in China, Japan, and Korea.
It consists essentially of a tablet or frame bearing parallel wires or grooves on which counters or beads are moved. A modern abacus consists of a wooden frame with beads on parallel wires, and a crossbar oriented perpendicular to the wires that divides the beads into two groups. Each column—that is, each wire—represents one place in the decimal system. The column farthest to the right is the ones column; the next column to the left is the tens column; and so on. In each column, there are five beads below the crossbar, each of which represent one unit, and two beads above the crossbar, each of which represent five units. For example, in the tens column, each of the group of five beads represents ten, and each of the group of two beads represents fifty. Beads that are to be counted as part of a number are placed against the crossbar.

At the Institute for Advanced Study in Princeton, New Jersey, Hungarian-American mathematician John von Neumann developed one of the first computers used to solve problems in mathematics, meteorology, economics, and hydrodynamics. Von Neumann's 1945 design for the Electronic Discrete Variable Automatic Computer (EDVAC)—in stark contrast to the designs of Aiken, his contemporary—was the first electronic computer design to incorporate a program stored entirely within its memory. This machine led to several others, some with clever names like ILLIAC, JOHNNIAC, and MANIAC.

Babbage's Difference Engine Considered by many to be a direct forerunner of the modern computer, the Difference Engine was able to compute mathematical tables. This woodcut shows a small portion of the ingenious machine, which was designed by Charles Babbage in the 1820s. Although the device did not have a memory, Babbage’s later idea for the Analytical Engine would have been a true, programmable

ENIAC

(Electronic Numerical Integrator And Computer), the first large-scale, general purpose, digital computer. ENIAC was initially built for the United States military to calculate the paths of artillery shells. It was later used to make calculations for nuclear weapons research, weather prediction, and wind tunnel design. ENIAC was introduced to thepublic in February 1946 and was used until October 1955.

UNIVAC UNIVAC, (UNIVersal Automatic Computer), the first electronic computer designed and sold to solve commercial problems. The UNIVAC contained about 5000 vacuum tubes, occupied 943 cubic feet, and weighed 8 tons. From 1951 to 1957 a variety of governmental and commercial customers bought a total of 48 UNIVAC computers.
Circuit Board and Transistors
In 1948, at Bell Telephone Laboratories, American physicists Walter Houser Brattain, John Bardeen, and William Bradford Shockley developed the transistor, a device that can act as an electric switch. The transistor had a tremendous impact on computer design, replacing costly, energy-inefficient, and unreliable vacuum tubes. Apple Macintosh Computer

The Apple Macintosh, released in 1984, was among the first personal computers to use a graphical user interface. A graphical user interface enables computer users to easily execute commands by clicking on pictures, words, or icons with a pointing device called a mouse. CM-5 Supercomputer

The Connection Machine CM-5 supercomputer is a massively parallel processing computer capable of many billions of floating point operations per second. The computer contains hundreds of processing units, similar to the central processing units (CPUs) in personal computers. The processing units are linked together in parallel so that multiple computations can be carried out simultaneously. Cray Supercomputer

The Cray-2 Supercomputer (designed by Seymour Cray of Cray Research, Eagan, MN) was first introduced in 1985, nine years after the first model, the Cray-1, was introduced. This type of supercomputer is used for mathematical studies of very complex problems, such as speech analysis, weather forecasting, and fundamental questions in physics and chemistry. Personal Computers at Home

Personal computers (PCs) have changed the way families track finances, write reports, and play games. PCs also help students enhance math, spelling, and reading skills.
Personal Computer Components


A typical personal computer has components to display and print information (monitor and laser printer); input commands and data (keyboard and mouse); retrieve and store information (CD-ROM and disk drives); and communicate with other computers (modem).

Computer System

A typical computer system consists of a central processing unit (CPU), input devices, storage devices, and output devices. The CPU consists of an arithmetic/logic unit, registers, control section, and internal bus. The arithmetic/logic unit carries out arithmetical and logical operations. The registers store data and keep track of operations. The control unit regulates and controls various operations. The internal bus connects the units of the CPU with each other and with external components of the system. For most computers, the principal input device is a keyboard. Storage devices include external floppy disc drives and internal memory boards. Output devices that display data include monitors and printers.