_+-five generation of computers-+_

in this week, i have learned about the five generation of computers. these are the summary of my learnings......

The First Generation: 1946-1958 (The Vacuum Tube Years)
The first generation computers were huge, slow, expensive, and often undependable. In 1946two Americans, Presper Eckert, and John Mauchly built the ENIAC electronic computer which used vacuum tubes instead of the mechanical switches of the Mark I. The ENIAC used thousands of vacuum tubes, which took up a lot of space and gave off a great deal of heat just like light bulbs do. The ENIAC led to other vacuum tube type computers like the EDVAC (Electronic Discrete Variable Automatic Computer) and the UNIVAC I (UNIVersal Automatic Computer).
The vacuum tube was an extremely important step in the advancement of computers. Vacuum tubes were invented the same time the light bulb was invented by Thomas Edison and worked very similar to light bulbs. It's purpose was to act like an amplifier and a switch. Without any moving parts, vacuum tubes could take very weak signals and make the signal stronger (amplify it). Vacuum tubes could also stop and start the flow of electricity instantly (switch). These two properties made the ENIAC computer possible.
The ENIAC gave off so much heat that they had to be cooled by gigantic air conditioners. However even with these huge coolers, vacuum tubes still overheated regularly. It was time for something new.

The Second Generation: 1959-1964 (The Era of the Transistor)
The transistor computer did not last as long as the vacuum tube computer lasted, but it was no less important in the advancement of computer technology. In 1947 three scientists, John Bardeen, William Shockley, and Walter Brattain working at AT&T's Bell Labs invented what would replace the vacuum tube forever. This invention was the transistor which functions like a vacuum tube in that it can be used to relay and switch electronic signals.
There were obvious differences between the transisitor and the vacuum tube. The transistor was faster, more reliable, smaller, and much cheaper to build than a vacuum tube. One transistor replaced the equivalent of 40 vacuum tubes. These transistors were made of solid material, some of which is silicon, an abundant element (second only to oxygen) found in beach sand and glass. Therefore they were very cheap to produce. Transistors were found to conduct electricity faster and better than vacuum tubes. They were also much smaller and gave off virtually no heat compared to vacuum tubes. Their use marked a new beginning for the computer. Without this invention, space travel in the 1960's would not have been possible. However, a new invention would even further advance our ability to use computers.

The Third Generation: 1965-1970 (Integrated Circuits - Miniaturizing the Computer)
Transistors were a tremendous breakthrough in advancing the computer. However no one could predict that thousands even now millions of transistors (circuits) could be compacted in such a small space. The integrated circuit, or as it is sometimes referred to as semiconductor chip, packs a huge number of transistors onto a single wafer of silicon. Robert Noyce of Fairchild Corporation and Jack Kilby of Texas Instruments independently discovered the amazing attributes of integrated circuits. Placing such large numbers of transistors on a single chip vastly increased the power of a single computer and lowered its cost considerably.
Since the invention of integrated circuits, the number of transistors that can be placed on a single chip has doubled every two years, shrinking both the size and cost of computers even further and further enhancing its power. Most electronic devices today use some form of integrated circuits placed on printed circuit boards-- thin pieces of bakelite or fiberglass that have electrical connections etched onto them -- sometimes called a mother board. These third generation computers could carry out instructions in billionths of a second. The size of these machines dropped to the size of small file cabinets. Yet, the single biggest advancement in the computer era was yet to be discovered.

The Fourth Generation: 1971-Today (The Microprocessor)
This generation can be characterized by both the jump to monolithic integrated circuits(millions of transistors put onto one integrated circuit chip) and the invention of the microprocessor (a single chip that could do all the processing of a full-scale computer). By putting millions of transistors onto one single chip more calculation and faster speeds could be reached by computers. Because electricity travels about a foot in a billionth of a second, the smaller the distance the greater the speed of computers.
However what really triggered the tremendous growth of computers and its significant impact on our lives is the invention of the microprocessor. Ted Hoff, employed by Intel (Robert Noyce's new company) invented a chip the size of a pencil eraser that could do all the computing and logic work of a computer. The microprocessor was made to be used in calculators, not computers. It led, however, to the invention of personal computers, or microcomputers.
It wasn't until the 1970's that people began buying computer for personal use. One of the earliest personal computers was the Altair 8800 computer kit. In 1975 you could purchase this kit and put it together to make your own personal computer. In 1977 the Apple II was sold to the public and in 1981 IBM entered the PC (personal computer) market.

Fifth Generation of Computer (present day computers)
Today we have all heard of Intel and its Pentium® Processors and now we know how it all got started. The computers of the next generation will have millions upon millions of transistors on one chip and will perform over a billion calculations in a single second. There is no end in sight for the computer movement.

by: Hanna Deborrah T. Ongking IV-Rizal

Learnings of the Week [ Rae Angeline S. Palen ]

In the discussions that we had, I learned the history about computers. I had difficulty in studying these lessons every time we had a quiz. For me, history is the hardest one to study about. But eventhough it is difficult, I also learned something.

As of this time, we studied about the four basic periods in computers [ pre-mechanical, mechanical, electromechanical, and electronic age ].

In the pre-mechanical period (3000 B.C. – 1450 A.D.), I learned that the first communication happened through speaking and simple drawings known as the petroglyths ( signs or simple figures carved in rocks ). Many people think that computing are 20th century inventions, yet, computing began when our ancient ancestors devised the first counting methods. The first numbering systems similar to those in use today were invented between 100 and 200 A.D. by Hindus in India who created a nine-digit numbering system and the concept of zero was developed around 875 A.D. And the first calculator is the abacus. Abacus is the man’s first recorded adding machine.

In the mechanical period ( 1450 – 1840 ), I learned that the first movable metal-type printing process was invented by Johann Gutenberg in 1450. The genuine name of Johann Gutenberg is “Johann Gensfleisch” and the gist of his name Johann Gutenberg is “John Beautiful Mountain”. Actually people who detained the job title "computer: one who works with numbers." In 1614, John Napier introduces logarithms. Logarithm allows multiplication and division reduces to addition and subtraction. In 1617, he make use of an ancient numerical scheme as the Arabian lattice, lays out a special version of the multiplication tables on a set of four-sided wooded rods, allowing users to multiply and divide large numbers and find square and cube roots. In 1623, Wilhelm Shickard invented the first mechanical calculator. It can work with six digits and carries digits across columns. It works, but never makes it beyond the prototype stage because it was burned-out in fire. In early 1600’s, William Oughtred invented the slide rule, an illustration of the early analog computer. In 1642, Blaise Pascal invented the first calculation machine called the Pascaline. In 1671, Gottfried Wilhelm von Leibniz invented a machine called the stepped reckoner that could multiply 5 digit and 12 digit numbers yielding up to 16 digit number. Babbage picked up the idea of punched card from Joseph Marie Jacquard’s loom. Arithmometer became the first mass-produced calculator developed by Charles Xavier Thomas de Colmar in 1820. Charles Babbage invented the first modern computer design: a steam powered adding machine called “the difference engine”. Babbage also invented the “analytical engine”. Babage’s difference engine and the analytical engine are regarded as the first “thinking machines”. Babage’s inventions earned the title “father of computers”. The first program was written by Lady Byron ( Ada Augusta Lovelace ). She is credited as being the first computer programmer.

In the electromechanical age ( 1840 – 1940 ), I well-read that the discovery of ways to harness electricity was the key advance made during this period. The beginnings of telecommunication are in the course of the voltaic battery, the telegraph and the telephone and radio. The first electric battery, known as the Voltaire pile was invented in 8th century by Alessandro Volta. Samuel F.J. Morse conceived of his version of an electromagnetic telegraph in 1832 and constructed an experiment version in 1815. In 1876, Alexander Graham Bell developed the first working telephone and transmitted his now famous quotation “Watson, come here, I want you”. Followed by the discovery that electrical waves travel through space and can fabricate an effect far from the point at which they originated by Guglielmo Marconi in 1894. These two events led to the invention of the radio. In 1852, George Boole develops binary algebra. In 1853, Pehr and Advard Scheutz complete their tabulating Machine, proficient of processing fifteen-digit numbers, printing out results and rounding off to eight digits. In 1885, Dorr Felt devises the Comptometer, a key driven adding and subtracting calculator and in 1889, he introduced the comptograph that contains a built-in printer. In 1890, Herman Hollerith was the first person to lucratively use punched cards. Hollerith company went to become the International Business Machines Corporation known today as IBM. In 1893, Otto Sweiger invented the first efficient four-function calculator known as the Millionaire. In 1906, Lee De Forest urbanized the vacuum tube which provides electricity controlled switch, a necessity for digital electronic computers. It was the first major electrical part of a computer, replacing manual switches. After the foreword of the vacuum tube, there were no longer tribulations with mechanical gears, pulleys or levers. It marked the end of mechanical computing and the beginnings of electronics in computer.

In the electronic period ( 1941 – present ), I well-read that the first programmable computer was built by Konrad Zuse called the Z3. A computer is programmable because it is competent of following instructions. In 1942, Howard Aiken, a PhD student of Harvard University built the Mark I “ The First Stored Program Computer”. And John Atanasoff and Clifford berry completed the first all-electronic computer the ABC (Atanasoff-Berry computer). ABC was the first computer to use electricity in the form of vacuum tubes to make electric computation possible.

We also studied about the first generations of computers and second generations of computers.

The first generation computers ( 1951 – 1958 ) used vacuum tubes as their main logic elements; punched cards to input and externally stock up data; and rotating magnetic drums for internal storage of data in programs written in machine language or assembly language. Besides, first-generation computers habitually broke down because of burned-out vacuum tubes. In 1945, Presper Eckert and John Mauchly developed the first operational electronic digital computer called ENIAC ( Electronic Numerical Integrator and Calculator). In 1951 the UNIVAC-1 became the first commercially accessible electronic computer. This computer was designed by Eckert and Mauchly and built by the Remington Rand Corporation. Between 1951 and 1953 magnetic core memory was developed. This memory consists of tiny ferrite “donuts” that were arranged on a lattice of wires. The polarity of their magnetization could be change or detected by fleeting current through the wires. Magnetic core memory was the fastest type of memory until the late 1980’s.

In the 1940s, a class of crystalline mineral materials called semiconductors could be used in the design of a device called a transistor to replace vacuum tubes. The second generation computers ( 1959 – 1963 ) used transistors as their electricity controlled switch instead of vacuum tubes. John Barden, Walter Brattain and William Shockley of Bell Telephone Laboratories invented the transistor. A transistor is a small, solid-state component designed to scrutinize the flow of the electric current. Transistors were smaller, faster, cheaper, required less power, and generate less heat than vacuum tubes. In computers, a transistor functions as an electronic switch or bridge. Transistors play an main role in electronic circuits. Circuits help formulate up electronic systems, and electronic systems are what make electronic computing feasible. Transistors allowed computers to communicate over telephone lines. The transistor gave way to the concept of parallel processor and multiprogramming. In 1961, Grace Hopper, the woman that found the first computer bug, finishes developing COBOL. In 1964, Digital Equipment Corporation (DEC), founded by Ken Olsen, make public the first minicomputer, the PDP-8. In 1965, Thomas Kurtz and John Kemeny of Dartmouth College developed BASIC (Beginners All Purpose Symbolic Instruction Code) as a computer language to aid in teaching the people how to program.