CONTENTSIntroduction To ComputersPeople associated with ComputersHistory of Computers
WHAT IS A COMPUTER? A computer is any device which aids humans inperforming various kinds of computations or calculations. In thatrespect the earliest computer was the abacus, used to perform basicarithmetic operations. While abacus may have technically been thefirst computer most people today associate the word “computer” withelectronic computers which were invented in the last century, andhave evolved into modern computers we know of today.
P E O P L E A S S O C I AT E D W I T H COMPUTERS Charles Babbage Alan Turing Tommy Flowers John V. Neumann Douglas Engelbart Steve Jobs Bill Gates
CHARLES BABBAGE Charles Babbage first came up with the idea of a mechanicalcomputer after seeing how numerical tables calculated by humans (calledcomputers) had a high-degree of error. He decided that by creating a device fordoing the same job, the errors could be eliminated. The difference engine was born:a machine capable of calculating the values of polynomial functions automatically.Regardless of the fact that his computer was never built while he was alive, Babbageopened the floodgates to a new world of computing machines. Without him, wemay not have the modern computers we have today.
ALAN TURING The initial machine Turing created was the Bombe: anelectromechanical device devised to help the code-breakers device the key of theday the Germans were using on their Enigma machines. Using a menu provided bythe codebreaking team from a crib (a selection of plaintext that corresponded tociphertext), the Bombe operators could quickly set up the machine and let itcalculate possible Enigma settings, which could then be verified by hand. The designon the Bombe was enhanced by Gordon Welchman, and the rest, as they say, ishistory.
TOMMY FLOWERS Another member of the Bletchley Park World War II team, Tommy Flowers wasinstrumental in building the worlds first electronic computer: Colossus. Theprinciple purpose of the machine was to break the Lorenz Cipher, used by high-level Germans, including Adolf Hitler. Colossus was the first programmable, digital,computer and revolutionary at the time. Its success in code breaking wasdemonstrated when Eisenhower was handed a decrypt showing that Hitler wasntgoing to move more troops into Normandy and the D-Day landings stood a high-chance of success.
JOHN V. NEUMANN It was von Neumann who came up with the computer architecturethats named after him. In a paper, he described an architecture inwhich both data and the program are stored in a computers memoryin the same address space, making for more flexible computers thatwere easier to program.
DOUGLAS ENGELBART Douglas Engelbart might not be a name thats well known,but he was a pioneer in the development of the modern computer. While working at theStanford Research Institute (SRI), he created a research department with an agendaentitled Augmenting Human Intellect: A Conceptual Framework. In other words, creatingmethods by which people would interact with computers. It was here that he created themouse (then a wooden shell with two metal wheels in it), still the de facto way that weinteract with computers today. He and his team also created bit-mapped screens,hypertext and some precursors to the graphical user interface (GUI). The research started here allowed Xerox to continue development and come up withthe basis of the windowed-operating system that we all use today.
STEVE JOBS In 1976 Steve Jobs, along with Stephen Wozniak and Ronald Wayne founded Apple.Although the company had early success with the Apple and, in particular, Apple II computers, itwas the original Macintosh (1984) that changed things: it was the first computer to have agraphical user interface and mouse rather than a command line interface.The Macintosh reallyhighlights Jobs ability to take existing technology and improve it, making it desirable. In the caseof this computer the graphical user interface had been developed by Xerox and the mouse byDouglas Engelbart; it was Apple that made them successful. Apple has produced the iPod, themost popular MP3 player in the world, the iPhone, which has sparked an entirely-new industrywith Apps and the iPad. With OS X and the move to Intel hardware, Apple is a leading companyin the personal computer market.
BILL GATES Whatever you may think about Bill Gates, theres no doubting theimpact that hes had on the computer market. Hes best known for founding Microsoft - aname thats synonymous with the personal computer market. Although Microsoft didntactually invent DOS (Tim Paterson of Seattle Computer Products) did, the company hasbased its fortunes on it, exclusively licensing the OS and later buying it outright to serviceIBMs PC. From DOS, Microsoft went on to create Windows - the most successfuloperating system ever, and used by the majority of people the world over.Gates is a keyfigure in the success of Microsoft - equal parts technology genius and business man, hespushed, cajoled and basically dictated the computer market.
HISTORY OF COMPUTERS First Generation Computers (1940s – 1950s) Second Generation Computers (1955 – 1960) Third Generation Computers (1960s) Fourth Generation Computers (1971 – present)
F I R S T G E N E R AT I O N COMPUTERS (1940’S -1950’S)First electronic computers used vacuum tubes, and they were huge andcomplex. The first general purpose electronic computer was the ENIAC(Electronic Numerical Integrator And Computer). It was digital,although it didn’t operate with binary code, and was reprogrammable tosolve a complete range of computing problems. It was programmedusing plugboards and switches, supporting input from an IBM cardreader, and output to an IBM card punch. It took up 167 square meters,weighed 27 tons, and consuming 150 kilowatts of power. It usedthousands of vacuum tubes, crystal diodes, relays, resistors, andcapacitors.
S E C O N D G E N E R AT I O N COMPUTERS(1955-1960)The second generation of computers came about thanks to theinvention of the transistor, which then started replacing vacuumtubes in computer design. Transistor computers consumed farless power, produced far less heat, and were much smallercompared to the first generation, albeit still big by today’sstandards.The first transistor computer was created at theUniversity of Manchester in 1953. The most popular oftransistor computers was IBM 1401. IBM also created the firstdisk drive in 1956, the IBM 350 RAMAC.
T H I R D G E N E R AT I O N COMPUTERS(1960-1970)The invention of the integrated circuits (ICs), also known as microchips, paved the wayfor computers as we know them today. Making circuits out of single pieces of silicon,which is a semiconductor, allowed them to be much smaller and more practical toproduce.First appeared minicomputers, first of which were still based on non-microchip transistors, and later versions of which were hybrids, being based on bothtransistors and microchips, such as IBM’s System/360. They were much smaller, andcheaper than first and second generation of computers, also known as mainframes.Minicomputers can be seen as a bridge between mainframes and microcomputers,which came later as the proliferation of microchips in computers grew.
F O U RT H G E N E R AT I O N COMPUTERS(1971-PRESENT)First microchips-based central processing units consisted of multiplemicrochips for different CPU components. The drive for ever greaterintegration and miniaturization led towards single-chip CPUs, where all of thenecessary CPU components were put onto a single microchip, called amicroprocessor. The first single-chip CPU, or a microprocessor, was Intel 4004.The advent of the microprocessor spawned the evolution of themicrocomputers, the kind that would eventually become personal computersthat we are familiar with today.