Wednesday, May 28, 2014
Monday, June 10, 2013
welcome history of computers
A computer is a general purpose device that can be programmed to carry out a finite set of arithmetic or logical operations. Since a sequence of operations can be readily changed, the computer can solve more than one kind of problem.
Conventionally, a computer consists of at least one processing element, typically a central processing unit (CPU) and some form of memory. The processing element carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on stored information. Peripheral devices allow information to be retrieved from an external source, and the result of operations saved and retrieved.
The Z3 by German inventor Konrad Zuse from 1941 was the first working programmable, fully automatic computing machine. Thus, Zuse is often regarded as the inventor of the computer.
The first electronic digital computers were developed between 1940 and 1945 in the United Kingdom and United States. Originally they were the size of a large room, consuming as much power as several hundred modern personal computers (PCs).[1] In this era mechanical analog computers were used for military applications.
Modern computers based on integrated circuits are millions to billions of times more capable than the early machines, and occupy a fraction of the space.[2] Simple computers are small enough to fit into mobile devices, and mobile computers can be powered by smallbatteries. Personal computers in their various forms are icons of the Information Age and are what most people think of as “computers.” However, the embedded computers found in many devices from MP3 players to fighter aircraft and from toys to industrial robots are the most numerous.
| Computer History Year/Enter | Computer History Inventors/Inventions | Computer History Description of Event |
| Konrad Zuse - Z1 Computer | First freely programmable computer. | |
| John Atanasoff & Clifford Berry ABC Computer | Who was first in the computing biz is not always as easy as ABC. | |
| Howard Aiken & Grace Hopper Harvard Mark I Computer | The Harvard Mark 1 computer. | |
| John Presper Eckert & John W. Mauchly ENIAC 1 Computer | 20,000 vacuum tubes later... | |
| Frederic Williams & Tom Kilburn Manchester Baby Computer & The Williams Tube | Baby and the Williams Tube turn on the memories. | |
| John Bardeen, Walter Brattain & Wiliam Shockley The Transistor | No, a transistor is not a computer, but this invention greatly affected the history of computers. | |
| John Presper Eckert & John W. Mauchly UNIVAC Computer | First commercial computer & able to pick presidential winners. | |
| International Business Machines IBM 701 EDPM Computer | IBM enters into 'The History of Computers'. | |
| John Backus & IBM FORTRAN Computer Programming Language | The first successful high level programming language. | |
| Stanford Research Institute, Bank of America, and General Electric ERMA and MICR | The first bank industry computer - also MICR (magnetic ink character recognition) for reading checks. | |
| Jack Kilby & Robert Noyce The Integrated Circuit | Otherwise known as 'The Chip' | |
| Steve Russell & MIT Spacewar Computer Game | The first computer game invented. | |
| Douglas Engelbart Computer Mouse & Windows | Nicknamed the mouse because the tail came out the end. | |
| ARPAnet | The original Internet. | |
| Intel 1103 Computer Memory | The world's first available dynamic RAM chip. | |
| Faggin, Hoff & Mazor Intel 4004 Computer Microprocessor | The first microprocessor. | |
| Alan Shugart &IBM The "Floppy" Disk | Nicknamed the "Floppy" for its flexibility. | |
| Robert Metcalfe & Xerox The Ethernet Computer Networking | Networking. | |
| Scelbi & Mark-8 Altair & IBM 5100 Computers | The first consumer computers. | |
| Apple I, II & TRS-80 & Commodore Pet Computers | More first consumer computers. | |
| Dan Bricklin & Bob Frankston VisiCalc Spreadsheet Software | Any product that pays for itself in two weeks is a surefire winner. | |
| Seymour Rubenstein & Rob Barnaby WordStar Software | Word Processors. | |
| IBM The IBM PC - Home Computer | From an "Acorn" grows a personal computer revolution | |
| Microsoft MS-DOS Computer Operating System | From "Quick And Dirty" comes the operating system of the century. | |
| Apple Lisa Computer | The first home computer with a GUI, graphical user interface. | |
| Apple Macintosh Computer | The more affordable home computer with a GUI. | |
| Microsoft Windows | Microsoft begins the friendly war with Apple. | |
Abacus
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| The Story: Calculation was a need from the early days when it was necessary to account to others for individual or group actions, particularly in relation to maintaining inventories (of flocks of sheep) or reconciling finances. Early man counted by means of matching one set of objects with another set (stones and sheep). The operations of addition and subtraction were simply the operations of adding or subtracting groups of objects to the sack of counting stones or pebbles. Early counting tables, named abaci, not only formalized this counting method but also introduced the concept of positional notation that we use today. The next logical step was to produce the first "personal calculator"—the abacus—which used the same concepts of one set of objects standing in for objects in another set, but also the concept of a single object standing for a collection of objects—positional notation. The Chinese abacus was developed about 5000 years ago. It was built out of wood and beads. It could be held and carried around easily. The abacus was so successful that its use spread form China to many other countries. The abacus is still in use in some countries today.The abacus does not actually do the computing, as today's calculators do. It helps people keep track of numbers as they do the computing. People who are good at using an abacus can often do calculations as quickly as a person who is using a calculator This one-for-one correspondence continued for many centuries even up through the many years when early calculators used the placement of holes in a dial to signify a count—such as in a rotary dial telephone. Although these machine often had the number symbol engraved alongside the dial holes, the user did not have to know the relationship between the symbols and their numeric value. Primitive people also needed a way to calculate and store information for future use. To keep track of the number of animals killed, they collected small rocks and pebbles in a pile. Each stone stood for one animal. Later they scratched notches and symbols in stone or wood to record and store information. Only when the process of counting and arithmetic became a more abstract process and different sizes of groups were given a symbolic representation so that the results could be written on a "storage medium" such as papyrus or clay did the process of calculation become a process of symbol manipulation. | |||||||||||||||||||
Napier's bones
Napier's Bones
Napier's bones, also called Napier's rods, are numbered rods which can be used to perform multiplication of any number by a number 2-9. By placing "bones" corresponding to the multiplier on the left side and the bones corresponding to the digits of the multiplicand next to it to the right, and product can be read off simply by adding pairs of numbers (with appropriate carries as needed) in the row determined by the multiplier. This process was published by Napier in 1617 an a book titled Rabdologia, so the process is also called rabdology.
There are ten bones corresponding to the digits 0-9, and a special eleventh bone that is used the represent themultiplier. The multiplier bone is simply a list of the digits 1-9 arranged vertically downward. The remainder of the bones each have a digit written in the top square, with the multiplication table for that digits written downward, with the digits split by a diagonal line going from the lower left to the upper right. In practice, multiple sets of bones were needed for multiplication of numbers containing repeated digits.
To multiply two numbers, arrange the bones as described above. The above illustration shows this process for 
. The computation proceeds from right to left, starting with the rightmost bone in the row determined by themultiplier. In this case, the last digit in the 7s row of the 6-bone is 2, so write down 2. Now add the two adjacent numbers in the same row to the left (i.e., the ones in the parallelogram) to obtain 
, which is the next digit, so we now have 72. The next sum is 
, so write down the 2 two obtain 272 and carry the 1. Proceeding to the next digit, it is 
(because of the carry), so write down the 4 to obtain 
and carry the 1. The leftmost digit is then 
(from the carry), giving the final answer 
.
While Napier's bones require manual accounting for carries, an ingenious extension known as Genaille rodsallows products to simply be read off directly, without the need for carries or even addition of pairs of adjacent digits.
. The computation proceeds from right to left, starting with the rightmost bone in the row determined by themultiplier. In this case, the last digit in the 7s row of the 6-bone is 2, so write down 2. Now add the two adjacent numbers in the same row to the left (i.e., the ones in the parallelogram) to obtain , which is the next digit, so we now have 72. The next sum is , so write down the 2 two obtain 272 and carry the 1. Proceeding to the next digit, it is (because of the carry), so write down the 4 to obtain and carry the 1. The leftmost digit is then (from the carry), giving the final answer .ENIAC
ENIAC ---Electronic Numerical Integrator And Computer)was the first electronic general-purpose computer. It was Turing-complete, digital, and capable of being reprogrammed to solve a full range of computing problems.
ENIAC was designed to calculate artillery firing tables for the United States Army'sBallistic Research Laboratory.[When ENIAC was announced in 1946 it was heralded in the press as a "Giant Brain".It had a speed of one thousand times that of electro-mechanical machines. This mathematical power, coupled with general-purpose programmability, excited scientists and industrialists. The inventors promoted the spread of these new ideas by conducting a series of lectures on computer architecture.
ENIAC's design and construction was financed by the United States Army, Ordnance Corps, Research and Development Command which was led by Major General Gladeon Marcus Barnes. He was Chief of Research and Engineering, the Chief of the Research and Development Service, Office of the Chief of Ordnance during World War II. The construction contract was signed on June 5, 1943, and work on the computer began in secret by the University of Pennsylvania's Moore School of Electrical Engineeringstarting the following month under the code name "Project PX". The completed machine was announced to the public the evening of February 14, 1946 and formally dedicated the next day at the University of Pennsylvania, having cost almost $500,000 (approximately $5,900,000 today). It was formally accepted by the U.S. Army Ordnance Corps in July 1946. ENIAC was shut down on November 9, 1946 for a refurbishment and a memory upgrade, and was transferred to Aberdeen Proving Ground, Maryland in 1947. There, on July 29, 1947, it was turned on and was in continuous operation until 11:45 p.m. on October 2, 1955.[2]
ENIAC was conceived and designed by John Mauchly and J. Presper Eckert of the University of Pennsylvania. The team of design engineers assisting the development included Robert F. Shaw (function tables), Jeffrey Chuan Chu (divider/square-rooter), Thomas Kite Sharpless (master programmer), Arthur Burks (multiplier), Harry Huskey(reader/printer) and Jack Davis (accumulators). ENIAC was named an IEEE Milestonein 1987.
UNIVAC
The UNIVAC I (UNIVersal Automatic Computer I) was the second commercial computer produced in the United States.It was designed principally by J. Presper Eckert and John Mauchly, the inventors of the ENIAC. Design work was started by their company, Eckert–Mauchly Computer Corporation, and was completed after the company had been acquired by Remington Rand (which later became part of Sperry, now Unisys). In the years before successor models of the UNIVAC I appeared, the machine was simply known as "theUNIVAC".
The first UNIVAC was accepted by the United States Census Bureau on March 31, 1951, and was dedicated on June 14 that year.The fifth machine (built for the U.S. Atomic Energy Commission) was used by CBS to predict the result of the 1952 presidential election. With a sample of just 1% of the voting population it famously predicted anEisenhower landslide while the conventional wisdom favored Stevenson.
IBM COMPUTERS
In July of 1980, IBM representatives met for the first time with Microsoft's Bill Gates to talk about writing an operating system for IBM's new hush-hush "personal" computer.
IBM had been observing the growing personal computer market for some time. They had already made one dismal attempt to crack the market with their IBM 5100. At one point, IBM considered buying the fledgling game company Atari to commandeer Atari's early line of personal computers. However, IBM decided to stick with making.
FRIST GENERATION OF COMPUTERS
First Generation (1941-1956)
World War gave rise to numerous developments and started off the computer age. Electronic Numerical Integrator and Computer (ENIAC) was produced by a partnership between University of Pennsylvannia and the US government. It consisted of 18,000 vacuum tubes and 7000 resistors. It was developed by John Presper Eckert and John W. Mauchly and was a general purpose computer. "Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 with a memory to hold both a stored program as well as data." Von Humanness's computer allowed for all the computer functions to be controlled by a single source.
Then in 1951 came the Universal Automatic Computer(UNIVAC I), designed by Remington rand and collectively owned by US census bureau and General Electric. UNIVAC amazingly predicted the winner of 1952, presidential elections, Dwight D. Eisenhower.
In first generation computers, the operating instructions or programs were specifically built for the task for which computer was manufactured. The Machine language was the only way to tell these machines to perform the operations. There was great difficulty to program these computers ,and more when there were some malfunctions. First Generation computers used Vacuum tubes and magnetic drums(for data storage).
SECOND GENERATION OF COMPUTERS
Second Generation Computers (1956-1963)
The invention of Transistors marked the start of the second generation. These transistors took place of the vacuum tubes used in the first generation computers. First large scale machines were made using these technologies to meet the requirements of atomic energy laboratories. One of the other benefits to the programming group was that the second generation replaced Machine language with the assembly language. Even though complex in itself Assembly language was much easier than the binary code.
Second generation computers also started showing the characteristics of modern day computers with utilities such as printers, disk storage and operating systems. Many financial information was processed using these computers.
In Second Generation computers, the instructions(program) could be stored inside the computer's memory. High-level languages such as COBOL (Common Business-Oriented Language) and FORTRAN (Formula Translator) were used, and they are still used for some applications noways.
THIRD GENERATION OF COMPUTER
Third Generation Computers (1964-1971)
Although transistors were great deal of improvement over the vacuum tubes, they generated heat and damaged the sensitive areas of the computer. The Interrelated Circuit(IC) was invented in 1958 by Jack Kilby. It combined electronic components onto a small silicon disc, made from quartz. More advancement made possible the fitings of even more components on a small chip or a semi conductor. Also in third generation computers, the operating systems allowed the machines to run many different applications. These applications were monitored and coordinated by the computer's memory.FOURTH GENERATION COMPUTERS
Fourth Generation (1971-Present)
Fourth Generation computers are the modern day computers. The Size started to go down with the improvement in the integerated circuits. Very Large Scale(VLSI) and Ultra Large scale(ULSI) ensured that millions of components could be fit into a small chip. It reduced the size and price of the computers at the same time increasing power, efficiency and reliability. "The Intel 4004 chip, developed in 1971, took the integrated circuit one step further by locating all the components of a computer (central processing unit, memory, and input and output controls) on a minuscule chip."
Due to the reduction of cost and the availability of the computers power at a small place allowed everyday user to benefit. First came the minicomputers, which offered users different applications, most famous of these the word processors and spreadsheets, which could be used by non-technical users. Video game systems like Atari 2600 generated the interest of general populace in the computers.
In 1981, IBM introduced personal computers for home and office use. "The number of personal computers in use more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs were being used." Computer size kept getting reduced during the years. It went down from Desktop to laptops to Palmtops. Machintosh introduecd Graphic User Interface in which the users didnt' have to type instructions but could use Mouse for the purpose.
The continued improvement allowed the networking of computers for the sharing of data. Local Area Networks(LAN) and Wide Area Network(WAN), were potential benefits, in that they could be implemented in corporations and everybody could share data over it. Soon the internet aand World Wide Web appeared on the computer scene and formented the Hi-Tech revolution of 90's.
FIFTH GENERATION COMPUTERS
Fifth Generation (Present and Beyond)
Fifth generations computers are only in the minds of advance research scientiets and being tested out in the laboratories. These computers will be under Artifical Intelligence(AI), They will be able to take commands in a audio visual way and carry out instructions. Many of the operations which requires low human intelligence will be perfomed by these computers.
Parallel Processing is coming and showing the possibiliy that the power of many CPU's can be used side by side, and computers will be more powerful than thoes unrs.der central processing. Advances in Super Conductor technology will greatly improve the speed of information traffic. Future looks bright for the computer.
your shield
your shield
HARDWARE
Case
A computer case (also known as a box) is a box that has bits of
computer in it (usually excluding the display, keyboard and mouse). A
computer case is sometimes referred to metonymously as a DMA meaing Doma
Media Alphonics. DMA was a common term in the earlier days of home
computers, when conjunctions other than the fatherboard were usually
housed in their own separate cases.
Power supply
Motherboard
The motherboard is the main component inside the case. It is a large
rectangular board with integrated circuitry that connects the other
parts of the computer including the CPU, the RAM, the disk drives (CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots.
- The CPU (Central Processing Unit) performs most of the calculations which enable a computer to function, and is sometimes referred to as the "brain" of the computer. It is usually cooled by a heat sink and fan. Most newer CPUs include an on-die Graphics Processing Unit (GPU).
- The Chipset, which includes the north bridge, mediates communication between the CPU and the other components of the system, including main memory.
- The Random-Access Memory (RAM) stores the code and data that are being actively accessed by the CPU.
- The Read-Only Memory (ROM) stores the BIOS that runs when the computer is powered on or otherwise begins execution, a process known as Bootstrapping, or "booting" or "booting up". The BIOS (Basic Input Output System) includes boot firmware and power management firmware. Newer motherboards use Unified Extensible Firmware Interface (UEFI) instead of BIOS.
- Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
- Current
- PCI Express: for expansion cards such as graphics, sound, network interfaces, TV tuners, etc.
- PCI: for other expansion cards.
- SATA: for disk drives.
- Obsolete
- AGP: superseded by PCI Express.
- ATA
- VLB: VESA Local Bus, superseded by AGP.
- EISA
- Micro Channel architecture
- ISA: expansion card slot format obsolete in PCs, but still used in industrial computers.
- Current
- Ports for external peripherals. These ports may be controlled directly by the south bridge I/O controller or provided by expansion cards attached to the motherboard.
- USB
- Memory Card
- FireWire
- eSATA
- SCSI
Expansion cards
The expansion card (also expansion board, adapter card or accessory card) in computing is a printed circuit board that can be inserted into an expansion slot of a computer motherboard or backplane to add functionality to a computer system via the expansion bus.An example of an expansion card is a sound card that enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have hardware support for sound integrated in the motherboard chipset but some users prefer to install a separate sound card as an upgrade for higher quality sound. Most sound cards, either built-in or added, have surround sound capabilities and 3-D sound effects.
Secondary storage devices
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is a core function and fundamental component of computers.
Fixed media
- Hard disk drives: a hard disk drive (HDD; also hard drive, hard disk, or disk drive)[2] is a device for storing and retrieving digital information, primarily computer data. It consists of one or more rigid (hence "hard") rapidly rotating discs (often referred to as platters), coated with magnetic material and with magnetic heads arranged to write data to the surfaces and read it from them.
- Solid-state drives: a solid-state drive (SSD), sometimes called a solid-state disk or electronic disk, is a data storage device that uses solid-state memory to store persistent data with the intention of providing access in the same manner of a traditional block I/O hard disk drive. SSDs are distinguished from traditional magnetic disks such as hard disk drives (HDDs) or floppy disk, which are electromechanical devices containing spinning disks and movable read/write heads.
- RAID array controller - a device to manage several internal or external hard disks and optionally some peripherals in order to achieve performance or reliability improvement in what is called a RAID array.
Removable media
- Optical Disc Drives for reading from and writing to various kinds of optical media, including Compact Discs such as CD-ROMs, DVDs, DVD-RAMs and Blu-ray Discs. Optical discs are the most common way of transferring digital video, and are popular for data storage as well.
- Floppy disk drives for reading and writing to floppy disks, an outdated storage media consisting of a thin disk of a flexible magnetic storage medium. These were once standard on most computers but are no longer in common use. Floppies are used today mainly for loading device drivers not included with an operating system release (for example, RAID drivers).
- Zip drives, an outdated medium-capacity removable disk storage system, for reading from and writing to Zip disks, was first introduced by Iomega in 1994.
- USB flash drive plug into a USB port and do not require a separate drive. USB flash drive is a typically small, lightweight, removable, and rewritable flash memory data storage device integrated with a USB interface. Capacities vary, from hundreds of megabytes (in the same range as CDs) to tens of gigabytes (surpassing Blu-ray discs but also costing significantly more).
- Memory card readers for reading from and writing to Memory cards, a flash memory data storage device used to store digital information. Memory cards are typically used on mobile devices. They are thinner, smaller and lighter than USB flash drives. Common types of memory cards are SD and MS.
- Tape drives read and write data on a magnetic tape, and are used for long term storage and backups.
Input and output peripherals
Input and output
devices are typically housed externally to the main computer chassis.
The following are either standard or very common to many computer
systems.
Input
Input devices allow the user to enter information into the system, or
control its operation. Very early computer systems had literal toggle
switches that could be tested by running programs as a simple form of
user input; modern personal computers have alphanumeric keyboards and
pointing devices to allow the user to interact with running software.
- Text input devices
- Keyboard - a device to input text and characters by depressing buttons (referred to as keys or buttons).
- Pointing devices
- Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
- Optical Mouse - uses light (laser technology) to determine mouse motion.
- Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.
- Touchscreen - senses the user pressing directly on the monitor.
- Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
- Gaming devices
- Joystick - a hand-operated pivoted stick whose position is transmitted to the computer.
- Game pad - a hand held game controller that relies on the digits (especially thumbs) to provide input.
- Game controller - a specific type of controller specialized for certain gaming purposes.
- Image, Video input devices
- Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
- Web cam - a video camera used to provide visual input that can be easily transferred over the internet.
- Audio input devices
- Microphone - an acoustic sensor that provides input by converting sound into electrical signals.
Output
Output devices display information in a human readable form. A
program-controlled pilot lamp would be a very simple example of an
output devices. Modern personal computers have full-screen
point-addressable graphic displays and often a printing device to
produce paper copies of documents and images.
- Printer - a device that produces a permanent human-readable text or graphic document.
- Laser printer
- Inkjet printer
- Dot matrix printer
- Thermal printer
- Computer monitors
- Speakers
See also
- Computer hardware
- History of computing hardware
- Networking hardware
- Glossary of computer terms
References
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created by oshan pbasara
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