� |
|
|
||||||||||||||||||||||||
|
Computer History
and Development ������ �Necessity is the mother of invention� this is certainly true in the case ��������� of the evolution and discovery of electronic computer machine.� METHOD
OF DATA PROCESSING
Sumerians -
(3000 BC) used clay tablets to record their transactions. They used sharp tools engrave
their writings on the clay. The first actual calculating mechanism known to us is the ABACUS, which is thought to have been invented by the Babylonians sometime between 1,000 BC and 500 BC, although some pundits are of the opinion that it was actually invented by the Chinese ABACUS is the first computing device, originated India, then developed and used by the Chinese. The japanese counterpart of Abacus is called Soroban. The abacus as we know it today, appeared circa 1200 A.D. in China; in Chinese, it is called suan-pan. The person operating the abacus performs calculations in their head and uses the abacus to keep track of the sums. Mechanical Data Processing
1642 Blaise Pascal(1623-1662) invented what he called a numerical wheel��calculator, PASCALINE. Pascaline, used eight movable dials to add sums up to eight figures long. Pascal's device used a base of ten to accomplish this. For example, as one dial moved ten notches, or one complete revolution, it moved the next dial - which represented the ten's column - one place. When the ten's dial moved one revolution, the dial representing the hundred's place moved one notch and so on. ��The drawback to the Pascaline, was its limitation to addition. Gottfried Wilhem von Leibniz (1646-1716) developed Pascal's ideas and, in�1671, introduced the Step Reckoner, a device which, as well as performing additions and subtractions, could multiply, divide, and evaluate square roots by series of stepped additions Pascal's and Leibniz's devices were the forebears of today's desk-top computers, and derivations of these machines continued to be produced until their electronic equivalents finally became readily available and affordable in the early 1970s. In 1867, Christopher Latham Sholes, Carlos Glidden, and Samual W. Soule�invented what they called the Type-Writer (the hyphen was discarded �some years later). Sholes keyboard is known to us as the QWERTY� keyboard, because of the ordering of the first six keys in the thir��row. His keyboard is interesting for at least two other reasons: firs� there was no key for the number '1', because the inventors deci�that the users could get by with the letter 'I'; and second, there�no shift key, because the first typewriters could only type upper�letters. The first shift-key typewriter (in which upperca�lowercase letters are made available on the same key) didn't��on the market until 1878, and it was quickly challenged by flavor which contained twice the number of keys, one uppercase and lowercase character. Electromechanical Data Processing
1820 Charles Xavier Thomas de Colmar, a Frenchman, invented a machine (calculator) that could perform the four basic arithmetic functions. The Arithometer. 1827 Joseph-Marie Jacquard invented Punched Card. A way of automatically controlling the warp and welf threads on a silk room by recording patterns of holes in a string of cards. In the years to come, variations on Jacquard's punched cards would find a variety of uses, including representing the music to be played by automated pianos and the storing of programs for computers 1822 Charles Babbage (1791-1871). Difference Engine / Analytical Engine. In 1822, Babbage proposed building a machine called the Difference Engine to automatically calculate mathematical tables. The Difference Engine was only partially completed when Babbage conceived the idea of another, more sophisticated machine called an Analytical Engine. The Analytical Engine was intended to use loops of Jacquard's punched cards to control an automatic calculator, which could make decisions based on the results of previous computations. This machine was also intended to employ several features subsequently used in modern computers, including sequential control, branching, and looping. Powered by steam and large as a locomotive, the machine would have a stored program and could perform calculations and print the results automatically. Augusta Ada King, Countess of Lovelace (1815-1842) instrumental in the machine's design. Lady Lovelace's fine understanding of the machine allowed her to create the instruction routines to be fed into the computer, making her the first female computer programmer. In the 1980's, the U.S. Defense Department named a programming language ADA in her honor. Elements of Babbage's steam-powered Engine outlined the basic elements of a modern general purpose computer. a) �input� devices in the form of perforated cards containing operating instructions b) "store" for memory of 1,000 numbers of up to 50 decimal digits long. c) "mill" with a control unit that allowed processing instructions in any sequence. d) �output� devices to produce printed results. Babbage borrowed the idea of punch cards to encode the machine's instructions from the Jacquard loom. The loom, produced in 1820 and named after its inventor, Joseph-Marie Jacquard, used punched boards that controlled the patterns to be woven. 1847 - 1854 George Boole Invents Boolean Algebra significant contributions in several areas of mathematics, but was immortalized for two works in 1847 and 1854, in which he represented logical expressions in a mathematical form now known as Boolean Algebra. Boole's work was all the more impressive because, with the exception of elementary school and a short time in a commercial school, he was almost completely self-educated. 1889 Herman Hollerith (1860-1929) invented Tabulating Machine Hollerith's method used cards to store data information which he fed into a machine that compiled the results mechanically. His first task was to find a faster way to compute the U.S. census. Instead of ten years, census takers compiled their results in just six weeks with Hollerith's machine. In addition to their speed, the punch cards served as a storage method for data and they helped reduce computational errors. Hollerith brought his punch card reader into the business world, founding Tabulating Machine Company in 1896, later to become International Business Machines (IBM) in 1924 after a series of mergers. 1931 Vannevar Bush (1890-1974) the American scientist, engineer, and politician designed an analog computer that could solve simple equations. The machine could solve complex differential equations that had long left scientists and mathematicians baffled. The machine was cumbersome because hundreds of gears and shafts were required to represent numbers and their various relationships to each other. 1940 John V. Atanasoff and Clifford Berry, envisioned an all-electronic digital computer that applied Boolean algebra to computer circuitry. (George Boole (1815-1864) who clarified the binary system of algebra, which stated that any mathematical equations could be stated simply as either true or false. Atanasoff and Berry had developed the first all-electronic computer by 1940. Their project, however, lost its funding and their work was overshadowed by similar developments by other scientists. Electronic Data Processing
� Five Generations of Modern Computers First Generation (1945-1956) 1941 German engineer Konrad Zuse had developed a computer, The Z3, to design airplanes and missiles. 1937 - 1944 Howard H. Aiken (1900-1973) American, Harvard engineer working with IBM, succeeded in producing an all-electronic calculator by 1944. The purpose of the computer was to create ballistic charts for the U.S. Navy. It was about half as long as a football field and contained about 500 miles of wiring. The Harvard-IBM Automatic Sequence Controlled Calculator, or Mark I. Many consider that the modern computer era commenced with the first large-scale automatic digital computer, which was developed between 1939 and 1944, or Mark 1943 - 1946 John Presper Eckert(1919-1995) and John W. Mauchly (1907-1980) Electronic Numerical Integrator and Computer (ENIAC) Consisting of 18,000 vacuum tubes, 70,000 resistors and 5 million soldered joints, the computer was such a massive piece of machinery that it consumed 160 kilowatts of electrical power, enough energy to light small town. ENIAC, unlike the Colossus and Mark I, was a general-purpose computer that computed at speeds 1,000 times faster than Mark I. If we ignore Atanasoff's machine and COLOSSUS, then the first true general-purpose electronic computer was the electronic numerical integrator and computer (ENIAC), which was constructed at the University of Pennsylvania between 1943 and 1946. 1945 John von Neumann (1903-1957) Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) with a memory to hold both a stored program as well as data. This "stored memory" technique as well as the "conditional control transfer," that allowed the computer to be stopped at any point and then resumed, allowed for greater versatility in computer programming. The key element to the von Neumann architecture was the central processing unit, which allowed all computer functions to be coordinated through a single source. First generation computers were characterized by the fact that operating 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. This made the computer difficult to program and limited its versatility and speed. Other distinctive features of first generation computers were the use of vacuum tubes (responsible for their breathtaking size) and magnetic drums for data storage. Second Generation Computers (1956-1963) 1948, the invention of the transistor greatly changed the computer's development. The transistor replaced the large, cumbersome vacuum tube in televisions, radios and computers. As a result, the size of electronic machinery has been shrinking ever since. These second generation computers were also of solid state design, and contained transistors in place of vacuum tubes. They also contained all the components we associate with the modern day computer: printers, tape storage, disk storage, memory, operating systems, and stored programs. It was the stored program and programming language that gave computers the flexibility to finally be cost effective and productive for business use. The stored program concept meant that instructions to run a computer for a specific function (known as a program) were held inside the computer's memory, and could quickly be replaced by a different set of instructions for a different function. More sophisticated high-level languages such as COBOL (Common Business-Oriented Language) and FORTRAN (Formula Translator) came into common use during this time, and have expanded to the current day. Third Generation Computers (1964-1971) Though transistors were clearly an improvement over the vacuum tube, they still generated a great deal of heat, which damaged the computer's sensitive internal parts. The quartz rock eliminated this problem. Jack Kilby, developed the integrated circuit (IC) in 1958. The IC combined three electronic components onto a small silicon disc, which was made from quartz. Scientists later managed to fit even more components on a single chip, called a semiconductor. As a result, computers became ever smaller as more components were squeezed onto the chip. Another third-generation development included the use of an operating system that allowed machines to run many different programs at once with a central program that monitored and coordinated the computer's memory. Fourth Generation (1971-Present) 1975 Bill Gates and Paul Allen founded Microsoft (which was to achieve a certain notoriety over the coming years), and in July of that year, MITS announced the availability of BASIC 2.0 on the Altair 8800. This BASIC interpreter, which was written by Gates and Allen, was the first reasonably high-level computer language program to be made available on a home computer. MITS sold 2,000 systems that year, which certainly made Ed Roberts a happy camper, while Microsoft had taken its first tentative step on the path toward world domination. 1976 Steve Wozniak and Steve Jobs (who had been fired with enthusiasm by the Altair 8800) finished work on a home-grown 6502-based computer which they called the Apple 1. After the integrated circuits, the only place to go was down - in size, that is. Large scale integration (LSI) could fit hundreds of components onto one chip. By the 1980's, very large scale integration (VLSI) squeezed hundreds of thousands of components onto a chip. Ultra-large scale integration (ULSI) increased that number into the millions. Such condensed power allowed everyday people to harness a computer's power. They were no longer developed exclusively for large business or government contracts. By the mid-1970's, computer manufacturers sought to bring computers to general consumers. These minicomputers came complete with user-friendly software packages that offered even non-technical users an array of applications, most popularly word processing and spreadsheet programs. Pioneers in this field were Commodore, Radio Shack and Apple Computers. In the early 1980's, arcade video games such as Pac Man and home video game systems such as the Atari 2600 ignited consumer interest for more sophisticated, programmable home computers. 1981 IBM introduced its personal computer (PC) for use in the home, office and schools. The 1980's saw an expansion in computer use in all three arenas as clones of the IBM PC made the personal computer even more affordable. As computers became more widespread in the workplace, new ways to harness their potential developed. As smaller computers became more powerful, they could be linked together, or networked, to share memory space, software, information and communicate with each other. As opposed to a mainframe computer, which was one powerful computer that shared time with many terminals for many applications, networked computers allowed individual computers to form electronic co-ops. Using either direct wiring, called a Local Area Network (LAN), or telephone lines, these networks could reach enormous proportions. A global web of computer circuitry, the Internet, for example, links computers worldwide into a single network of information.� The most popular use today for computer networks such as the Internet is electronic mail, or E-mail, which allows users to type in a computer address and send messages through networked terminals across the office or across the world. Fifth Generation (Present and Beyond) Defining the fifth generation of computers is somewhat difficult because the field is in its infancy. The most famous example of a fifth generation computer is the fictional HAL9000 from Arthur C. Clarke's novel, 2001: A Space Odyssey. HAL performed all of the functions currently envisioned for real-life fifth generation computers. With artificial intelligence, HAL could reason well enough to hold conversations with its human operators, use visual input, and learn from its own experiences. (Unfortunately, HAL was a little too human and had a psychotic breakdown, commandeering a spaceship and killing most humans on board.) Though the wayward HAL9000 may be far from the reach of real-life computer designers, many of its functions are not. Using recent engineering advances, computers are able to accept spoken word instructions (voice recognition) and imitate human reasoning. The ability to translate a foreign language is also moderately possible with fifth generation computers. This feat seemed a simple objective at first, but appeared much more difficult when programmers realized that human understanding relies as much on context and meaning as it does on the simple translation of words. Many advances in the science of computer design and technology are coming together to enable the creation of fifth-generation computers. Two such engineering advances are parallel processing, which replaces von Neumann's single central processing unit design with a system harnessing the power of many CPUs to work as one. Another advance is superconductor technology, which allows the flow of electricity with little or no resistance, greatly improving the speed of information flow. Computers today have some attributes of fifth generation computers. For example, expert systems assist doctors in making diagnoses by applying the problem-solving steps a doctor might use in assessing a patient's needs. It will take several more years of development before expert systems are in widespread use. Computers may be compared on the basis of cost, capacity (memory size, data wordlength, size of secondary storage), performance (speed). They may be classed broadly as:
|
|||||||||||||||||||||||||
|
� Information Processing (Computation)
Information Storage
System Memory
The Processor
Hard Disk Drives
Information Movement and Communication
How the Computer Computes
Digital and Analog Information
The Mathematics of Computing
|
|||||||||||||||||||||||||
