COMPUTERS
Q.What is a computer?
Ans.A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations.
PARTS OF COMPUTER
MONITOR:-A computer monitor is an electronic device that shows pictures. A monitor is usually used to see programs on a computer. The main difference between a monitor and a television is that a monitor does not have a television turne to change channels. A monitor may be used to watch television if it is connected to a device that has a television tuner. Some models of monitor can be used as a television, and some televisions are used with computers. A monitor has a better display resolution than a television to make it easier to see smaller letters and graphics on.C.P.U.:-The central processing unit (CPU) is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. Two typical components of a CPU are the arithmetic logic unit (ALU), which performs arithmetic and logical operations, and the control unit (CU), which extracts instructions from memory and decodes and executes them, calling on the ALU when necessary.
KEYBOARD:-In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. Following the decline of punch cards and paper tape, interaction via teleprinter-style keyboards became the main input device for computers.A keyboard typically has characters engraved or printed on the keys and each press of a key typically corresponds to a single written symbol. However, to produce some symbols requires pressing and holding several keys simultaneously or in sequence.
MOUSE:-A computer mouse is used to tell a computer what to do, including moving the cursor and choosing things on the screen.On most computers, the user can move the mouse to move the cursor in the same direction. If there is something on the screen that the user wants to choose, he can move the cursor over it and "click" the mouse button. The right mouse button is used to open menus that are different depending on where the cursor is. The other mouse buttons can do different things, depending on the software. A mouse can have 1 to 6 buttons to click, but most mice have two or three.
SPEAKER:-Computer speakers, or multimedia speakers, are speakers external to a computer, that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier.Some computer displays have rather basic speakers built-in. Laptops come with integrated speakers. Restricted space available in laptops means these speakers usually produce low-quality sound.Computer speakers range widely in quality and in price. The computer speakers typically packaged with computer systems are small, plastic, and have mediocre sound quality.Despite being designed for computers, computer speakers are electrically compatible with the aforementioned stereo components.
U.P.S.:-An uninterruptible power supply, also uninterruptible power source, UPS orbattery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide instantaneous or near-instantaneous protection from input power interruptions by means of one or more attached batteries and associated electronic circuitry for low power users, and or by means of diesel generators and flywheels for high power users.PRINTERS:-A printer is a piece of hardware for a computer. It is a device that must be connected to a computer which allows a user to print items on paper, such as letters and pictures. It can also work with digital cameras to print directly without the use of a computer.Today, the following types of printers are in regular use:
- Inkjet printers, also sometimes called bubble jet printers use colored ink they put on a paper.
- Plotters are large format inkjet printers, or printers that use special pens.
- Laser printers transfer tiny particles of toner onto the paper.
SCANNER:-In computing, an image scanner—often abbreviated to just scanner—is a device that optically scans images, printed text, handwriting, or an object, and converts it to a digital image. Common examples found in offices are variations of the desktop (or flatbed) scanner where the document is placed on a glass window for scanning. Hand-held scanners, where the device is moved by hand, have evolved from text scanning "wands" to 3D scanners used for industrial design, reverse engineering, test and measurement, orthotics, gaming and other applications.
JOYSTICKS:-A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks, also known as 'control columns', are the principal control in the cockpit of many civilian and military aircraft, either as a center stick or side-stick. They often have supplementary switches on them to control other aspects of the aircraft's flight.Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer.
GENERATIONS OF COMPUTER
- First Generation (1940-1956) Vacuum Tubes
:- The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.
- Second Generation (1956-1963) Transistors
Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN.
- Third Generation (1964-1971) Integrated Circuits
The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitorsand interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.
- Fourth Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.
5 Fifth Generation (Present and Beyond) Artificial Intelligence
:- The Fifth Generation Computer Systems project (FGCS) was an initiative by Japan's Ministry of International Trade and Industry, begun in 1982, to create a "fifth generation computer" (see History of computing hardware) which was supposed to perform much calculation using massive parallel processing. It was to be the end result of a massive government/industry research project in Japan during the 1980s. It aimed to create an "epoch-making computer" with supercomputer-like performance and to provide a platform for future developments in artificial intelligence.The term fifth generation was intended to convey the system as being a leap beyond existing machines. Computers using vacuum tubes were called the first generation; transistors and diodes, the second; integrated circuits, the third; and those using microprocessors, the fourth. Whereas previous computer generations had focused on increasing the number of logic elements in a single CPU, the fifth generation, it was widely believed at the time, would instead turn to massive numbers of CPU for added performance.
SOME MORE FACTS ABOUT COMPUTER
:- The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first-generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.
Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.
Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitorsand interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.
5 Fifth Generation (Present and Beyond) Artificial Intelligence:- The Fifth Generation Computer Systems project (FGCS) was an initiative by Japan's Ministry of International Trade and Industry, begun in 1982, to create a "fifth generation computer" (see History of computing hardware) which was supposed to perform much calculation using massive parallel processing. It was to be the end result of a massive government/industry research project in Japan during the 1980s. It aimed to create an "epoch-making computer" with supercomputer-like performance and to provide a platform for future developments in artificial intelligence.The term fifth generation was intended to convey the system as being a leap beyond existing machines. Computers using vacuum tubes were called the first generation; transistors and diodes, the second; integrated circuits, the third; and those using microprocessors, the fourth. Whereas previous computer generations had focused on increasing the number of logic elements in a single CPU, the fifth generation, it was widely believed at the time, would instead turn to massive numbers of CPU for added performance.
SOME MORE FACTS ABOUT COMPUTER
. (1). An Amd 1400 chip running without a heatsink gets as hot as 370 degrees.
(2). Sea gate introduced the first hdd for pcs in 1979.It held 5 M.B of data.
(3). If you opened up the case of the original Macintosh, you will find 47 signatures
one for each member of Apple's Macintosh division as of 1982.
(4). The first computer company to register for a domain name was digital
equipment corporation.
(5). Did you know Apple & Sun came very close to a merger in 1996.
(6). The technology contained in a single game boy unit in 2000 exceeds all
the computing power that was used to put the first man on moon in 1969.
(7). Hewlett Packard was started at a garage in Palo Alto in 1939.
(2). Sea gate introduced the first hdd for pcs in 1979.It held 5 M.B of data.
(3). If you opened up the case of the original Macintosh, you will find 47 signatures
one for each member of Apple's Macintosh division as of 1982.
(4). The first computer company to register for a domain name was digital
equipment corporation.
(5). Did you know Apple & Sun came very close to a merger in 1996.
(6). The technology contained in a single game boy unit in 2000 exceeds all
the computing power that was used to put the first man on moon in 1969.
(7). Hewlett Packard was started at a garage in Palo Alto in 1939.
TYPES OF COMPUTERS
Microcomputers (Personal computers)
Microcomputers are the most common type of computers used by people today, whether in a workplace, at school or on the desk at home. The term “microcomputer” was introduced with the advent of single chip microprocessors. The term "microcomputer" itself is now practically ananachronism.These computers include:- Desktop computers – A case and a display, put under and on a desk.
- In-car computers (“carputers”) – Built into a car, for entertainment, navigation, etc.
- Game consoles – Fixed computers specialized for entertainment purposes (video games).
A separate class is that of mobile devices:- Laptops, notebook computers and Palmtop computers – Portable and all in one case. Varying sizes, but other than smartbooks expected to be “full” computers without limitations.
- Tablet computer – Like laptops, but with a touch-screen, sometimes entirely replacing the physical keyboard.
- Smartphones, smartbooks and PDAs (personal digital assistants) – Small handheld computers with limited hardware.
- Programmable calculator– Like small handhelds, but specialised on mathematical work.
- Handheld game consoles – The same as game consoles, but small and portable.
Minicomputers (Midrange computers)A minicomputer (colloquially, mini) is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the smallest multi-user systems (mainframe computers) and the largest single-user systems (microcomputers or personal computers). The contemporary term for this class of system is midrange computer, such as the higher-end SPARC, POWER and Itanium -based systems fromSun Microsystems, IBM and Hewlett-Packard.
Mainframe computersThe term mainframe computer was created to distinguish the traditional, large, institutional computer intended to service multiple users from the smaller, single user machines. These computers are capable of handling and processing very large amounts of data quickly. Mainframe computers are used in large institutions such as government, banks and large corporations. its measured in MIPS (Million instructions per second) and reponds up to 100's of million users at one time.
SupercomputerA supercomputer is focused on performing tasks involving intense numerical calculations such as weather forecasting, fluid dynamics, nuclear simulations, theoretical astrophysics, and complex scientific computations. A supercomputer is a computer that is at the frontline of current processing capacity, particularly speed of calculation. The term supercomputer itself is rather fluid, and the speed of today's supercomputers tends to become typical of tomorrow's ordinary computer. Supercomputer processing speeds are measured in floating point operations per second or FLOPS. An example of a floating point operation is the calculation of mathematical equations in real numbers. In terms of computational capability, memory size and speed, I/O technology, and topological issues such as bandwidth and latency, supercomputers are the most powerful, are very expensive, and not cost-effective just to perform batch or transaction processing. Transaction processing is handled by less powerful computers such as server computers or mainframes.
