1940s - Early 1950s: First Generation Computers
Probably the most important contributor concerning the theoretical basis for the digital computers that were developed in the 1940s was  Alan Turing, an English mathematician and logician. In 1936 he created the Turing machine, which was originally conceived as a mathematical tool that could infallibly recognize undecidable propositions. Although he instead proved that there cannot exist any universal method of determination, Turing's machine represented an idealized mathematical model that reduced the logical structure of any computing device to its essentials. His basic scheme of an input/output device, memory, and central processing unit became the basis for all subsequent digital computers.
The onset of the Second World War led to an increased funding for computer projects, which hastened technical progress, as governments sought to develop computers to exploit their potential strategic importance.
By 1941 the German engineer Konrad Zuse had developed a computer, the Z3, to design airplanes and missiles. Two years later the British completed a secret code-breaking computer called Colossus to decode German messages and by 1944 the Harvard engineer Howard H. Aiken had produced an all-electronic calculator, whose purpose was to create ballistic charts for the U.S. Navy.
Also spurred by the war the Electronic Numerical Integrator and Computer (ENIAC), a general-purpose computer, was produced by a partnership between the U.S. government and the University of Pennsylvania (1943). Consisting of 18.000 vacuum tubes, 70.000 resistors and 5 million soldered joints, the computer was such a massive piece of machinery (floor space: 1,000 square feet) that it consumed 160 kilowatts of electrical power, enough energy to dim lights in an entire section of a bigger town.
Concepts in computer design that remained central to computer engineering for the next 40 years were developed by the Hungarian-American mathematician John von Neumann in the mid-1940s. By 1945 he created the Electronic Discrete Variable Automatic Computer (EDVAC) with a memory to hold both a stored program as well as data. The key element of the Neumann architecture was the central processing unit (CPU), which allowed all computer functions to be coordinated through a single source. One of the first commercially available computers to take advantage of the development of the CPU was the UNIVAC I (1951). Both the U.S. Census bureau and General Electric owned UNIVACs (Universal Automatic Computer).
Characteristic for first generation computers was the fact, that instructions were made-to-order for the specific task for which the computer was to be used. Each computer had a different binary-coded program called a machine language that told it how to operate. Therefore computers were difficult to program and limited in versatility and speed. Another feature of early computers was that they used vacuum tubes and magnetic drums for storage.
|
ARPAnet
ARPAnet was the small network of individual computers connected by leased lines that marked the beginning of today's global data networks. Being an experimental network mainly serving the purpose to test the feasibility of wide area networks, the possibility of remote computing, it was created for resource sharing between research institutions, not for messaging services like E-mail. Although research was sponsored by US military, ARPAnet was not designed for directly martial use but to support military-related research.
In 1969 ARPANET went online and links the first two computers, one of them located at the University of California, Los Angeles, the other at the Stanford Research Institute.
But ARPAnet has not become widely accepted before it was demonstrated in action to a public of computer experts at the First International Conference on Computers and Communication in Washington, D. C. in 1972.
Before it was decommissioned in 1990, NSFnet, a network of scientific and academic computers funded by the National Science Foundation, and a separate new military network went online in 1986. In 1988 the first private Internet service providers offered a general public access to NSFnet. Beginning in 1995, after having become the backbone of the Internet in the USA, NSFnet was turned over to a consortium of commercial backbone providers. This and the launch of the World Wide Web added to the success of the global data network we call the Net.
In the USA commercial users already outnumbered military and academic users in 1994.
Despite the rapid growth of the Net, most computers linked to it are still located in the United States.
|
TEXTBLOCK 1/1 // URL: http://world-information.org/wio/infostructure/100437611663/100438659338