Computer is a programmable machine. This means it can execute a programmed list of instructions and respond to new instructions that it is given. Today, however, the term is most often used to refer to the desktop and laptop computers that most people use. When referring to a desktop model, the term "computer" technically only refers to the computer itself -- not the monitor, keyboard, and mouse. Still, it is acceptable to refer to everything together as the computer. If you want to be really technical, the box that holds the computer is called the "system unit."
Saturday, March 7, 2009
What is Computer?
Computer is a programmable machine. This means it can execute a programmed list of instructions and respond to new instructions that it is given. Today, however, the term is most often used to refer to the desktop and laptop computers that most people use. When referring to a desktop model, the term "computer" technically only refers to the computer itself -- not the monitor, keyboard, and mouse. Still, it is acceptable to refer to everything together as the computer. If you want to be really technical, the box that holds the computer is called the "system unit."
Introduction
Without knowing past nobody cannot expect better future. This blog is created on nthe basis of History of computer. So this will help you to acchieve you a better future.
1939
1940
1941
Konrad Zuse finishes the Z3 computer. The Z3 was an early computer built by German engineer Konrad Zuse working in complete isolation from developments elsewhere. Using 2,300 relays, the Z3 used floating point binary arithmetic and had a 22-bit word length. The original Z3 was destroyed in a bombing raid of Berlin in late 1943. However, Zuse later supervised a reconstruction of the Z3 in the 1960s which is currently on display at the Deutsches Museum in Berlin.
The first Bombe is completed. Based partly on the design of the Polish “Bomba,” a mechanical means of decrypting Nazi military communications during WWII, the British Bombe design was greatly influenced by the work of computer pioneer Alan Turing and others. Many bombes were built. Together they dramatically improved the intelligence gathering and processing capabilities of Allied forces. [Computers]
1942
1943
Project Whirlwind begins. During World War II, the U.S. Navy approached the Massachusetts Institute of Technology (MIT) about building a flight simulator to train bomber crews. The team first built a large analog computer, but found it inaccurate and inflexible. After designers saw a demonstration of the ENIAC computer, they decided on building a digital computer. By the time the Whirlwind was completed in 1951, the Navy had lost interest in the project, though the U.S. Air Force would eventually support the project which would influence the design of the SAGE program.
The Relay Interpolator is completed. The U.S. Army asked Bell Labs to design a machine to assist in testing its M-9 Gun Director. Bell Labs mathematician George Stibitz recommended using a relay-based calculator for the project. The result was the Relay Interpolator, later called the Bell Labs Model II. The Relay Interpolator used 440 relays and since it was programmable by paper tape, it was used for other applications following the war.
1944
Harvard Mark-1 is completed. Conceived by Harvard professor Howard Aiken, and designed and built by IBM, the Harvard Mark-1 was a room-sized, relay-based calculator. The machine had a fifty-foot long camshaft that synchronized the machine’s thousands of component parts. The Mark-1 was used to produce mathematical tables but was soon superseded by stored program computers.
The first Colossus is operational at Bletchley Park. Designed by British engineer Tommy Flowers, the Colossus was designed to break the complex Lorenz ciphers used by the Nazis during WWII. A total of ten Colossi were delivered to Bletchley, each using 1,500 vacuum tubes and a series of pulleys transported continuous rolls of punched paper tape containing possible solutions to a particular code. Colossus reduced the time to break Lorenz messages from weeks to hours. The machine’s existence was not made public until the 1970s.
1945
John von Neumann wrote "First Draft of a Report on the EDVAC" in which he outlined the architecture of a stored-program computer. Electronic storage of programming information and data eliminated the need for the more clumsy methods of programming, such as punched paper tape — a concept that has characterized mainstream computer development since 1945. Hungarian-born von Neumann demonstrated prodigious expertise in hydrodynamics, ballistics, meteorology, game theory, statistics, and the use of mechanical devices for computation. After the war, he concentrated on the development of Princeton´s Institute for Advanced Studies computer and its copies around the world.
On September 9th, Grace Hopper recorded the first actual computer "bug" — a moth stuck between the relays and logged at 15:45 hours on the Harvard Mark II. Hopper, a rear admiral in the U.S. Navy, enjoyed successful careers in academia, business, and the military while making history in the computer field. She helped program the Harvard Mark I and II and developed the first compiler, A-0. Her subsequent work on programming languages led to COBOL, a language specified to operate on machines of different manufacturers.
Konrad Zuse began work on Plankalkul (Plan Calculus), the first algorithmic programming language, with an aim of creating the theoretical preconditions for the formulation of problems of a general nature. Seven years earlier, Zuse had developed and built the world´s first binary digital computer, the Z1. He completed the first fully functional program-controlled electromechanical digital computer, the Z3, in 1941. Only the Z4 — the most sophisticated of his creations — survived World War II.
1946
In February, the public got its first glimpse of the ENIAC, a machine built by John Mauchly and J. Presper Eckert that improved by 1,000 times on the speed of its contemporaries.Start of project: 1943
Completed: 1946
Programmed: plug board and switches
Speed: 5,000 operations per second
Input/output: cards, lights, switches, plugs
Floor space: 1,000 square feet
Project leaders: John Mauchly and J. Presper Eckert.
1947
1948
IBM´s Selective Sequence Electronic Calculator computed scientific data in public display near the company´s Manhattan headquarters. Before its decommissioning in 1952, the SSEC produced the moon-position tables used for plotting the course of the 1969 Apollo flight to the moon. Speed: 50 multiplications per second
Input/output: cards, punched tape
Technology: 20,000 relays, 12,500 vacuum tubes
Project leader: Wallace Eckert
Norbert Wiener published "Cybernetics," a major influence on later research into artificial intelligence. He drew on his World War II experiments with anti-aircraft systems that anticipated the course of enemy planes by interpreting radar images. Wiener coined the term "cybernetics" from the Greek word for "steersman."
In addition to "cybernetics," historians note Wiener for his analysis of brain waves and for his exploration of the similarities between the human brain and the modern computing machine capable of memory association, choice, and decision making.
Claude Shannon´s "The Mathematical Theory of Communication" showed engineers how to code data so they could check for accuracy after transmission between computers. Shannon identified the bit as the fundamental unit of data and, coincidentally, the basic unit of computation.
1949
Maurice Wilkes assembled the EDSAC, the first practical stored-program computer, at Cambridge University. His ideas grew out of the Moore School lectures he had attended three years earlier.
For programming the EDSAC, Wilkes established a library of short programs called subroutines stored on punched paper tapes.
Technology: vacuum tubes
Speed: 714 operations per second
The Manchester Mark I computer functioned as a complete system using the Williams tube for memory. This University machine became the prototype for Ferranti Corp.´s first computer.
Start of project: 1947
Completed: 1949
Add time: 1.8 microseconds
Input/output: paper tape, teleprinter, switches
Memory size: 128 + 1024 40-digit words
Memory type: cathode ray tube, magnetic drum
Technology: 1,300 vacuum tubes
Floor space: medium room
Project leaders: Frederick Williams and Tom Kilburn
1950
Engineering Research Associates of Minneapolis built the ERA 1101, the first commercially produced computer; the company´s first customer was the U.S. Navy. It held 1 million bits on its magnetic drum, the earliest magnetic storage devices. Drums registered information as magnetic pulses in tracks around a metal cylinder. Read/write heads both recorded and recovered the data. Drums eventually stored as many as 4,000 words and retrieved any one of them in as little as five-thousandths of a second.
The National Bureau of Standards constructed the SEAC (Standards Eastern Automatic Computer) in Washington as a laboratory for testing components and systems for setting computer standards. The SEAC was the first computer to use all-diode logic, a technology more reliable than vacuum tubes, and the first stored-program computer completed in the United States. Magnetic tape in the external storage units (shown on the right of this photo) stored programming information, coded subroutines, numerical data, and output.
The National Bureau of Standards completed its SWAC (Standards Western Automatic Computer) at the Institute for Numerical Analysis in Los Angeles. Rather than testing components like its companion, the SEAC, the SWAC had an objective of computing using already-developed technology.
Alan Turing´s philosophy directed design of Britain´s Pilot ACE at the National Physical Laboratory. "We are trying to build a machine to do all kinds of different things simply by programming rather than by the addition of extra apparatus," Turing said at a symposium on large-scale digital calculating machinery in 1947 in Cambridge,
Mass.Start of project: 1948
Completed: 1950
Add time: 1.8 microseconds
Input/output: cards
Memory size: 352 32-digit words
Memory type: delay lines
Technology: 800 vacuum tubes
Floor space: 12 square feet
Project leader: J. H. Wilkinson
1951
MIT´s Whirlwind debuted on Edward R. Murrow´s "See It Now" television series. Project director Jay Forrester described the computer as a "reliable operating system," running 35 hours a week at 90-percent utility using an electrostatic tube memory.
Start of project: 1945
Add time: .05 microseconds
Memory size: 2048 16-digit words
Technology: 4,500 vacuum tubes, 14,800 diodes
Project leaders: Jay Forrester and Robert Everett
England´s first commercial computer, the Lyons Electronic Office, solved clerical problems. The president of Lyons Tea Co. had the computer, modeled after the EDSAC, built to solve the problem of daily scheduling production and delivery of cakes to the Lyons tea shops. After the success of the first LEO, Lyons went into business manufacturing computers to meet the growing need for data processing systems.
The UNIVAC I delivered to the U.S. Census Bureau was the first commercial computer to attract widespread public attention. Although manufactured by Remington Rand, the machine often was mistakenly referred to as the "IBM UNIVAC." Remington Rand eventually sold 46 machines at more than $1 million each.F.O.B. factory $750,000 plus $185,000 for a high speed printer.
Speed: 1,905 operations per second
Input/output: magnetic tape, unityper, printer
Memory size: 1,000 12-digit words in delay lines
Memory type: delay lines, magnetic tape
Technology: serial vacuum tubes, delay lines, magnetic tape
Floor space: 943 cubic feet
Cost: F.O.B. factory $750,000 plus $185,000 for a high speed printer
Project leaders: J. Presper Eckert and John Mauchly
1952
1953
1954
A silicon-based junction transistor, perfected by Gordon Teal of Texas Instruments Inc., brought the price of this component down to $2.50. A Texas Instruments news release from May 10, 1954, read, "Electronic "brains" approaching the human brain in scope and reliability came much closer to reality today with the announcement by Texas Instruments Incorporated of the first commercial production of silicon transistors kernel-sized substitutes for vacuum tubes."
The company became a household name when the first transistor radio incorporated Teal´s invention. The radio, sold by Regency Electronics for $50, launched the world into a global village of instant news and pop music.
The IBM 650 magnetic drum calculator established itself as the first mass-produced computer, with the company selling 450 in one year. Spinning at 12,500 rpm, the 650´s magnetic data-storage drum allowed much faster access to stored material than drum memory machines.
Alan Turing was found dead at age 42. He had published his seminal paper, "On Computable Numbers," in 1936, as well as posing significant questions about judging "human intelligence" and programming and working on the design of several computers during the course of his career.
A mathematical genius, Turing proved instrumental in code-breaking efforts during World War II. His application of logic to that realm would emerge even more significantly in his development of the concept of a "universal machine."
1955
Felker and Harris program TRADIC, AT&T Bell Laboratories announced the first fully transistorized computer, TRADIC. It contained nearly 800 transistors instead of vacuum tubes. Transistors — completely cold, highly efficient amplifying devices invented at Bell Labs — enabled the machine to operate on fewer than 100 watts, or one-twentieth the power required by comparable vacuum tube computers.
In this photograph, J. H. Felker (left) gives instructions to the TRADIC computer by means of a plug-in unit while J. R. Harris places numbers into the machine by flipping simple switches. The computer occupied only 3 cubic feet.
First meeting of SHARE, the IBM users group, convened. User groups became a significant educational force allowing companies to communicate innovations and users to trade information.
Herbert Simon and Allen Newell unveiled Logic Theorist software that supplied rules of reasoning and proved symbolic logic theorems. The release of Logic Theorist marked a milestone in establishing the field of artificial intelligence.
1956
Burroughs buys Electrodata. Calculator manufacturer Burroughs gained entry to the computer industry by purchasing the southern California company Electrodata Corporation. The combined firm became a giant in the calculating machine business and expanded into electronics and digital computers when these technologies developed. Burroughs created many computer systems in the 1960s and 1970s and eventually merged with the makers of the Sperry Rand (maker of Univac computers) to form Unisys.
MIT researchers built the TX-0, the first general-purpose, programmable computer built with transistors. For easy replacement, designers placed each transistor circuit inside a "bottle," similar to a vacuum tube. Constructed at MIT´s Lincoln Laboratory, the TX-0 moved to the MIT Research Laboratory of Electronics, where it hosted some early imaginative tests of programming, including a Western movie shown on TV, 3-D tic-tac-toe, and a maze in which mouse found martinis and became increasingly inebriated.
At MIT, researchers began experimentation on direct keyboard input on computers, a precursor to today´s normal mode of operation. Doug Ross wrote a memo advocating direct access in February; five months later, the Whirlwind aided in such an experiment.
The era of magnetic disk storage dawned with IBM´s shipment of a 305 RAMAC to Zellerbach Paper in San Francisco. The IBM 350 disk file served as the storage component for the Random Access Method of Accounting and Control. It consisted of 50 magnetically coated metal platters with 5 million bytes of data. The platters, stacked one on top of the other, rotated with a common drive shaft.
1957
A group of engineers led by Ken Olsen left MIT´s Lincoln Laboratory founded a company based on the new transistor technology. In August, they formally created Digital Equipment Corp. It initially set up shop in a largely vacant woolen mill in Maynard, Mass., where all aspects of product development — from management to manufacturing — took place.
In Minneapolis, the original Engineering Research Associates group led by Bill Norris left Sperry Rand to form a new company, Control Data Corp., which soon released its model 1604 computer.
Sperry Rand released a commercial compiler for its UNIVAC. Developed by Grace Hopper as a refinement of her earlier innovation, the A-0 compiler, the new version was called MATH-MATIC. Earlier work on the A-0 and A-2 compilers led to the development of the first English-language business data processing compiler, B-0 (FLOW-MATIC), also completed in 1957. FLOW-MATIC served as a model on which to build with input from other sources.
A new language, FORTRAN (short for FORmula TRANslator), enabled a computer to perform a repetitive task from a single set of instructions by using loops. The first commercial FORTRAN program ran at Westinghouse, producing a missing comma diagnostic. A successful attempt followed.
1958
The air defense system operated on the AN/FSQ-7 computer (known as Whirlwind II during its development at MIT) as its central computer. Each computer used a full megawatt of power to drive its 55,000 vacuum tubes, 175,000 diodes and 13,000 transistors.