the computer chronicles

8/3/2019 The Computer Chronicles

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The Computer Chronicles

2010 Alton C. Crews Middle School Spring Issue 2010 \

FREE & ExcellentStudent Web design App.

NEWS FLASH!A New Generation of Computers is about to be Announcedby Roderick Hames

In the beginning ...A generation refers to the state of improvement in the development of a product.

This term is also used in the different advancements of computer technology. With eachnew generation, the circuitry has gotten smaller and more advanced than the previous

generation before it. As a result of the miniaturization, speed, power, and memory of

computers has proportionally increased. New discoveries are constantly being developedthat affect the way we live, work and play.

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 ENIACelectronic 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 othervacuum 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 ofcomputers. 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 anamplifierand aswitch. Without any moving parts, vacuum tubes could take very weaksignals 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.
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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, butit 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 thevacuum 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 thevacuum 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 abundantelement (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 betterthan 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 theComputer)

Transistors were a tremendous breakthrough in advancing the computer. However

no one could predict that thousands even now millions of transistors (circuits) could becompacted 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 ofFairchild Corporation and Jack Kilby ofTexas Instrumentsindependently 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 beplaced 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 ofbakelite orfiberglass that have electrical connections etched onto them -- sometimes

called a mother board.

These third generation computers could carry out instructions in billionths of asecond. 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.


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The Fourth Generation: 1971-Today (TheMicroprocessor)

This generation can be characterized by both the jump to monolithicintegratedcircuits(millions oftransistors put onto one integrated circuit chip) and the invention of

the microprocessor (a single chip that could do all the processing of a full-scalecomputer). 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 itssignificant impact on our lives is the invention of the microprocessor. Ted Hoff,

employed by Intel (RobertNoyce'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 microprocessorwas 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.

Today we have all heard ofIntel 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 billioncalculations in a single second. There is no end in sight for the computer movement.

Questions

Directions: Answer each of the questions after reading the article above. Write in

complete sentences. You must think and be creative with your answers.

1. In each of the 4 generations what was the cause for the increase ofspeed, power,

ormemory?

2. Why did the ENIAC and other computers like it give off so much heat? (Be veryspecific)

3. What characteristics made the transistors better than the vacuumtube?

4. How was space travel made possible through the invention of transistors?5. What did the microprocessorallow the computers to do? and What was the

microprocessor's original purpose?

6. When was the first computer offered to the public and what was its name?7. What was Robert Noyce and Jack Kilby known for?


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8. Intel was started by who?

9. What is monolithicintegratedcircuits?

10. How do you think society will be different if scientists are able to create a chipthat will perform a trillion operations in a singlesecond?

Processors of old and new

One of the first ICs 386 Processor Pentium Processor The New Processors

This site was created byRoderick Hamesfor the primary purpose of teaching and demonstrating computer & business skills..

Any distribution or copying without the express or written consent ofAlton C. Crews Middle School or its creator is strictly prohibited.

***Any questions, comments or suggestions concerning

this page or this Web site should be forwarded toRoderick Hames, Computer Science / Business Education Teacher

Copyright 2009, Alton C. Crews Middle School: CS Dept - Articles
mailto:[email protected]?subject=Computer%20Chronmailto:[email protected]?subject=Computer%20Chronmailto:[email protected]?subject=Computer%20chronhttp://www.crews.org/curriculum/ex/compsci/articles/articles.htmlmailto:[email protected]?subject=Computer%20Chronmailto:[email protected]?subject=Computer%20chronhttp://www.crews.org/curriculum/ex/compsci/articles/articles.html


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Dated: Aug. 13, 2004

Related Categories

Computer Beginners Guides

By Najmi

Related Article:History, Origins, and Various Generations of Computers, Charles

Babbage - Father of Computing

Jan. 01, 2010 Update: Minor Tweaks were done for keywords.

The history of computer development is often referred to in reference to the different

generations of computing devices. A generation refers to the state of improvement in the

product development process. This term is also used in the different advancements ofnew computer technology. With each new generation, the circuitry has gotten smaller and

more advanced than the previous generation before it. As a result of the miniaturization,

speed, power, and computer memory has proportionally increased. New discoveries areconstantly being developed that affect the way we live, work and play.

Each generation of computers is characterized by major technological development that

fundamentally changed the way computers operate, resulting in increasingly smaller,

cheaper, more powerful and more efficient and reliable devices. Read about each

generation and the developments that led to the current devices that we use today.

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. A magnetic drum,also referred toas drum, is a metal cylinder coated with magnetic iron-

oxide material on which data and programs can be stored.

Magnetic drums were once use das a primary storage

device but have since been implemented as auxiliarystorage devices.

The tracks on a magnetic drum are assigned to channels

located around the circumference of the drum, formingadjacent circular bands that wind around the drum. A

single drum can have up to 200 tracks. As the drum rotates at a speed of up to 3,000 rpm,

the device's read/write heads deposit magnetized spots on the drum during the write
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operation and sense these spots during a read operation. This action is similar to that of a

magnetic tape or disk drive.

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 to perform operations, and they could only solveone problem at a time. Machine languages are the only languages understood by

computers. While easily understood by computers, machine languages are almostimpossible for humans to use because they consist entirely of numbers. Computer

Programmers, therefore, use eitherhigh level programming languages or an assembly

language programming. An assembly language contains the same instructions as amachine language, but the instructions and variables have names instead of being just

numbers.

Programs written in high level programming languages retranslated into assembly

language or machine language by a compiler. Assembly language program retranslated

into machine language by a program called an assembler (assembly language compiler).

Every CPU has its own unique machine language. Programs must be rewritten or

recompiled, therefore, to run on different types of computers. Input was based onpunch

card and paper tapes, 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.

Acronym for Electronic Numerical Integrator And Computer, the world's first operational

electronic digital computer, developed by Army Ordnance to compute World War IIballistic firing tables. The ENIAC, weighing 30 tons, using 200 kilowatts of electric

power and consisting of 18,000 vacuum tubes,1,500 relays, and hundreds of thousands ofresistors,capacitors, and inductors, was completed in 1945. In addition to ballistics, the

ENIAC's field of application included weather prediction, atomic-energy calculations,

cosmic-ray studies, thermal ignition,random-number studies, wind-tunnel design, and

other scientific uses. The ENIAC soon became obsolete as the need arose for fastercomputing speeds.

Second Generation - 1956-1963:

Transistors

Transistors replaced vacuum tubes and

ushered in the second generation

computer. Transistor is a device composed

of semiconductor material that amplifies asignal or opens or closes a circuit.

Invented in 1947 at Bell Labs, transistors

have become the key ingredient of all


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Instruction Set: The set of instructions that the microprocessor can execute.

Bandwidth: The number of bits processed in a single instruction.

Clock Speed: Given in megahertz (MHz), the clock speed determines how manyinstructions per second the processor can execute.

In both cases, the higher the value, the more powerful the CPU. For example, a 32-bit

microprocessor that runs at 50MHz is more powerful than a 16-bitmicroprocessor that

runs at 25MHz.

What in the first generation filled an entire room could now fit in the palm of the hand.

The Intel 4004chip, 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.

Abbreviation of central processing unit, and pronounced as separate letters. The CPU isthe brains of the computer. Sometimes referred to simply as the processor or central

processor, the CPU is where most calculations take place. In terms of computing

power,the CPU is the most important element of a computer system.

On large machines, CPUs require one or more printed circuit boards. On personalcomputers and small workstations, the CPU is housed in a single chip called a

microprocessor.

Two typical components of a CPU are:

The arithmetic logic unit (ALU), which performs arithmetic and logical

operations.

The control unit, which extracts instructions from memory and decodes and

executes them, calling on the ALU when necessary.

In 1981 IBM introduced its first computer for the home user, and in 1984 Appleintroduced the Macintosh. Microprocessors also moved out of the realm of desktopcomputers and into many areas of life as more and more everyday products began to use

microprocessors.

As these small computers became more powerful, they could be linked together to formnetworks, which eventually led to the development of the Internet. Fourth generation

computers also saw the development of GUI's, the mouse and handheld devices


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Fifth Generation - Present and Beyond: Artificial

Intelligence

Fifth generation computing devices, based on artificialintelligence, are still in development,though there are some

applications, such as voice recognition, that are being usedtoday.

Artificial Intelligence is the branch of computer science concerned with makingcomputers behave like humans. The term was coined in 1956 by John McCarthy at the

Massachusetts Institute of Technology. Artificial intelligence includes:

Games Playing: programming computers to play games such as chess andcheckers

Expert Systems: programming computers to make decisions in real-life situations

(for example, some expert systems help doctors diagnose diseases based on

symptoms)

Natural Language: programming computers to understand natural human

languages

Neural Networks: Systems that simulate intelligence by attempting to reproducethe types of physical connections that occur in animal brains

Robotics: programming computers to see and hear and react to other sensory

stimuli

Currently, no computers exhibit full artificial intelligence (that is, are able to simulatehuman behavior). The greatest advances have occurred in the field of games playing. The

best computer chess programs are now capable of beating humans. In May,1997, an IBMsuper-computer called Deep Blue defeated world chess champion Gary Kasparov in a

chess match.

In the area of robotics, computers are now widely used in assembly plants, but they are

capable only of very limited tasks. Robots have great difficulty identifying objects based

on appearance or feel, and they still move and handle objects clumsily.


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Natural-language processing offers the greatest potential rewards because it would allow

people to interact with computers without needing any specialized knowledge. You could

simply walk up to a computer and talk to it. Unfortunately, programming computers tounderstand natural languages has proved to be more difficult than originally thought.

Some rudimentary translation systems that translate from one human language to another

are in existence, but they are not nearly as good as human translators.

There are also voice recognition systems that can convert spoken sounds into writtenwords, but they do not understand what they are writing; they simply take dictation. Even

these systems are quite limited -- you must speak slowly and distinctly.

In the early 1980s, expert systems were believed to represent the future of artificial

intelligence and of computers in general. To date, however, they have not lived up toexpectations. Many expert systems help human experts in such fields as medicine and

engineering, but they are very expensive to produce and are helpful only in special

situations.

Today, the hottest area of artificial intelligence is neural networks, which are proving

successful in an umber of disciplines such as voice recognition and natural-language

processing.

There are several programming languages that are known as AI languages because theyare used almost exclusively for AI applications. The two most common are LISP and

Prolog.

Related Article:Discover Computer History

Voice Recognition

The field of computer science that deals

with designing computer systems that canrecognize spoken words. Note that voice

recognition implies only that the computer

can take dictation, not that it understandswhat is being said. Comprehending human

languages falls under a different field of

computer science called natural language

processing. A number of voice recognition

systems are available on the market. Themost powerful can recognize thousands of

words. However, they generally require an extended training session during which thecomputer system becomes accustomed to a particular voice and accent.Such systems are

said to be speaker dependent.

Many systems also require that the speaker speak slowly and distinctly and separate each

word with a short pause. These systems are called discrete speech systems. Recently,
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great strides have been made in continuous speech systems -- voice recognition systems

that allow you to speak naturally. There are now several continuous-speech systems

available for personal computers.

Because of their limitations and high cost, voice recognition systems have traditionally

been used only in a few specialized situations. For example, such systems are useful ininstances when the user is unable to use a keyboard to enter data because his or her hands

are occupied or disabled. Instead of typing commands, the user can simply speak into aheadset. Increasingly, however, as the cost decreases and performance improves, speech

recognition systems are entering the mainstream and are being used as an alternative to

keyboards.

The use of parallel processing and superconductors is helping to make artificialintelligence a reality. Parallel processing is the simultaneous use of more than one CPU

to execute a program. Ideally, parallel processing makes a program run faster because

there are more engines (CPUs) running it. In practice, it is often difficult to divide a

program in such a way that separate CPUs can execute different portions withoutinterfering with each other.

Most computers have just one CPU, but some models have several. There are even

computers with thousands of CPUs. With single-CPU computers, it is possible to performparallel processing by connecting the computers in a network. However, this type of

parallel processing requires very sophisticated software called distributed processing

software.

Note that parallel processing differs from multitasking, in which a single CPU executesseveral programs at once.

Parallel processing is also called parallel computing.

Quantum computation and molecular and nano-technology will radically change the face

of computers in years to come. First proposed in the 1970s, quantum computing relies onquantum physics by taking advantage of certain quantum physics properties of atoms or

nuclei that allow them to work together as quantum bits, or qubits, to be the computer's

processor and memory. By interacting with each other while being isolated from theexternal environment,qubits can perform certain calculations exponentially faster than

conventional computers.

Qubits do not rely on the traditional binary nature of computing. While traditionalcomputers encode information into bits using binary numbers, either a 0or 1, and canonly do calculations on one set of numbers at once, quantum computers encode

information as a series of quantum-mechanical states such as spin directions of electrons

or polarization orientations of a photon that might represent a 1 or a 0, might represent acombination of the two or might represent a number expressing that the state of the qubit

is somewhere between 1 and 0, or a superposition of many different numbers at once. A

quantum computer can doan arbitrary reversible classical computation on all the numbers


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simultaneously, which a binary system cannot do, and also has some ability to produce

interference between various different numbers. By doing a computation on many

different numbers at once,then interfering the results to get a single answer, a quantumcomputer has the potential to be much more powerful than a classical computer of the

same size.In using only a single processing unit, a quantum computer can naturally

perform myriad operations in parallel.

Quantum computing is not well suited for tasks such as word processing and email, but itis ideal for tasks such as cryptography and modeling and indexing very large databases.

Nanotechnology is a field of science whose goal is to control individual atoms and

molecules to create computer chips and other devices that are thousands of times smaller

than current technologies permit. Current manufacturing processes use lithography toimprint circuits on semiconductor materials. While lithography has improved

dramatically over the last two decades -- to the point where some manufacturing plants

can produce circuits smaller than one micron(1,000 nanometers) -- it still deals with

aggregates of millions of atoms. It is widely believed that lithography is quicklyapproaching its physical limits. To continue reducing the size of semiconductors, new

technologies that juggle individual atoms will be necessary. This is the realm ofnanotechnology.

Although research in this field dates back to Richard P. Feynman's classic talk in 1959,

the term nanotechnology was first coined by K. Eric Drexler in1986 in the book Engines

of Creation.

In the popular press, the term nanotechnology is sometimes used to refer to any sub-micron process,including lithography. Because of this, many scientists are beginning to

use the term molecular nanotechnology when talking about true nanotechnology at themolecular level.

The goal of fifth-generation computing is to develop devices that respond to natural

language input and are capable of learning and self-organization.

Here natural language means a human language. For example, English, French, and

Chinese are natural languages. Computer languages, such as FORTRAN and C,are not.

Probably the single most challenging problem in computer science is to developcomputers that can understand natural languages. So far, the complete solution to this

problem has proved elusive, although great deal of progress has been made. Fourth-generation languages are the programming languages closest to natural languages.

The Internet has sunk its claws deep in peoples hearts and minds. Users now want tostay connected to the Net all the time so that none of the correspondence is delayed or

they dont miss any opportunity to click on a prize. One tends to forget the amount of

manpower that is being consumed while playing lotto online or downloading a new flashgame. The gum on the screen is so sticky that nobody gets time to shift his or her eye


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from the monitor. This is a destructive trait for employees in Mission Critical

Environments. Thanks to the proliferation of the Internet in the corporate sector, how

employees utilize their online time at workplace is now a critical debate.

Increasingly, companies are finding that workers tend to get sidetracked indulging in

personal entertainment or catching up with the friends via Instant Messengers resulting inhours of wasted company time. Employees who do waste precious company time in

mindless Net pursuits are termed as CyberSlackers. Over the past three years, severalorganizations such as The New York Times, Rolls Royce and Xerox have fired workers

for abusing company Net accounts. Two popular reasons why more workers are finding

themselves out of job are downloading porn and sending out obscene emails to friendsand colleagues.In the age of the connected, a company can therefore never expect to meet

targets if checks are not applied and policies are not outlined for employees to spend their

online time. What factors should organizations keep in mind while drafting the groundrules for their employees?

Is the time spent in various online non-productive activities an appreciable thing? Is the costing of Internet usage worth the companys monthly expense?

Is the time spent on the Net beneficial for the company or are the employeeswasting a major chunk of the account in individual pursuits?

There are three main reasons why companies should be concerned about their employees

surf habits:

Loss of productivity

Legal liability Waste of Bandwidth

Loss of Productivity

If employees are using the Internet for non-work related purposes, then this results in

reduced productivity and ultimate loss in profits. On an average, workers browse theInternet more at the office as opposed to the odd few hours at home due to presence of

proxy settings on their PCs, which allows full-time connectivity.

The US Treasury Department recently monitored the Internal Revenue Services

(IRS)Workforces Internet use

They found that activities such as personal email, chat, online shopping and personalfinance and stocks accounted for 51% of employees time spent online. The top non-work

Web activity favored by IRS officials was surfing financial websites. Chat and email ran

a close second, followed by miscellaneous activities including visiting adult sites, searchrequests, and looking at or downloading streaming media.

Time is an asset and a misuse of that asset is just as wrong as the misuses of any of other

assets that the company holds. As with any project, meeting a deadline is always a core


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issue. Internet addiction makes meeting crucial deadlines an impossible task and one

never realizes how his precious time is wasted whiling away on the Internet checking

horoscope and news trivia.

Legal Liability

Employees are betraying their companys trust and abusing their online time when they

download material that is illegal or inappropriate. An employer can face legal risks at the

hands of careless employees. Companies are also at legal risk for copyright violationwhen employees download protected mp3 files or pirated software.

Employees can also sue their employers if a co-worker has downloaded pornographic or

racist materials. Clearly, it has become essential for companies to be aware of what there

employees are downloading from the Internet, and for them to take steps to avoid liabilityby introducing employee Internet management strategies. Following habits should not be

entertained in a regular office:

Uploading illegal materials to a public Web site, illegally gained access to a

network, server, by hacking or cracking passwords.

Sending out computer viruses or denial of service attack to the Internet.

Sending illegal material such as child pornography to co-workers.

Emailing hate letters or slanderous letters over the Internet.

Posting unfounded corporate rumors on stock market bulletin boards.

Sending emails that may offend co-workers and are covered under sexual

harassment laws.

Otherwise engage in similar online behavior.

Employees who are treated with dignity and respect, who take pride in their organizationand its ethics, tend to respect the assets of that organization. As stealing pen, stationary,

and hardware is unethical. Similarly acting indifferent on the Net during office hours is abad techie trait.

Waste of Bandwidth

As broadband applications over the Internet continue to become increasingly popular,

corporate networks are becoming bottlenecked; Streaming media, mp3 files, video and

audio files, large graphic files, are increasing network crashes.For many companies,network quality of service (QoS) may be their most important business asset. If QoS is

dragging, so is the companys ability to keep pace with competition. Todays Internet letsemployees buy products, chat with friends, visit their kids at daycare, listen to Real audiofeeds and play interactive games. As a result, the bandwidth increases.

Preventive Measures


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While monitoring and filtering software can be effective for managing current Internet

abusers in the workplace, a more effective means of Employee Internet Management is

via preventative measures.

Draft Company Internet access policy

Company-wide education about proper Net use

Internet Access Policy

Most companies already require employees to sign a basic contract indicating what

acceptable Internet use is, the fact that employees may be monitored without indication,and that unacceptable Internet abuse is grounds for termination.

Company-Wide Education About Proper Net Usage

Surprisingly, very few companies offer seminars or educational materials for employees

to learn about the ramifications of Internet abuse. By educating employees on howabusing the Internet has a negative impact on both the self and the company, many of

these problems outlined in this article may be alleviated.

Boss Plays Big Brother

It is certainly not ethical to poke into someones inbox. Given the importance of user

privacy in the cyber age, it is important not to overlook how bosses can step over the line,closely monitoring their employees surf trails. If your organization is drafting a policy

paper for workers Net use, make sure it is well balanced in light of the standards set by

International privacy advocates. The Electronic Frontier Foundation maintains an archive

of information pertinent to work privacy.

Work First

Wasting company Internet time, intentionally or otherwise, is wrong. It cuts into our

abilities to do the job, to be productive and competitive. And in todays market place,being competitive is the key to survival. Internet is an excellent research tool and its use

should benefit the companys cause. As workers, our online time should produce new

growth strategies for the company rather than mindless IMing.

For any response,


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History of generations of Computers

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The computers that you see and use today hasn't come off by any

inventor at one go. Rather it took centuries of rigorous research work to

reach the present stage. And scientists are still working hard to make it

better and better. But that is a different story.

First, let us see when the very idea of computing with a machine or

device, as against the conventional manual calculation, was given a

shape.

Though experiments were going on even earlier, it dates back to the17th century when the first such successful device came into being.

Edmund Gunter, an English mathematician, is credited with itsdevelopment in 1620. Yet it was too primitive to be recognized even as

the forefather of computers. The first mechanical digital calculatingmachine was built in 1642 by the French scientist-philosopher Blaise

Pascal. And since then the ideas and inventions of many

mathematicians, scientists, and engineers paved the way for thedevelopment of the modern computer in following years.

But the world has had to wait for yet another couple of centuries toreach the next milestone in developing a computer. Then it was the

English mathematician and inventor Charles Babbage who did thewonder with his works during 1830s. In fact, he was the first to work on

a machine that can use and store values of large mathematical tables.The most important thing of this machine is its use in recording electric

impulses, coded in the very simple binary system, with the help of onlytwo kinds of symbols.

This is quite a big leap closer to the basics on which computers todaywork. However, there was yet a long way to go. And, compared to

present day computers, Babbage's machine could be regarded as more

of high-speed counting devices. For, they could only work on numbersalone!

The Boolean algebra developed in the 19th century removed thenumbers-alone limitation for these counting devices. This technique of

mathematics, invented by Boole, helped correlate the binary digits withour language. For instance, the values of 0s are related with false

statements and 1s with the true ones. British mathematician Alan


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Turing made further progress with the help of his theory of a computing

model. Meanwhile the technological advancements of the 1930s helpedmuch in furthering the advancement of computing devices.

But the direct forefathers of present-day computer systems evolved in

about 1940s. The Harvard Mark 1 Computer designed by Howard Aiken

is the world's first digital computer which made use of electro-mechanical devices. It was developed jointly by the International

Business Machines (IBM) and the Harvard University in 1944.

But the real breakthrough was the concept of the stored-program

computer. This was when the Hungarian-American mathematician Johnvon Neumann introduced the Electronic Discrete Variable Automatic

Computer (EDVAC). The idea--that instructions as well as data shouldbe stored in the computer's memory for better results--made this device

totally different from its counting device type of forerunners. And sincethen computers have increasingly become faster and more powerful.

Still, as against the present day's personal computers, they had the

simplest form of designs. It was based on a single CPU performingvarious operations, like, addition, multiplication and so on. And these

operations would be performed following an order of instructions, calledprogram, to produce the desired result.

This form of design, was followed, with a little change even in the

advanced versions of computers developed later. This changed versionsaw a division of the CPU into memory and arithmetic logical unit (ALU)

parts and a separate input and output sections.

In fact, the first four generations of computers followed this as theirbasic form of design. It was basically the type of hardware used that

caused the difference over the generation. For instance, the firstgeneration variety was based on vacuum tube technology. This wasupgraded with the coming up of the transistors, and printed circuit

board technology in the 2nd generations. It was further upgraded by thecoming up of integrated circuit chip technology where the little chips

replaced a large number of components. Thus the size of computer was

greatly reduced in the 3rd generation, while it become more powerful.But the real marvel came during the 1970s. It was with the introduction

of the very large scale integrated technology (VLSI) in the 4thgeneration. Aided by this technology a tiny microprocessor can store

millions of pieces of data.

And based on this technology the IBM introduced its famous Personal

Computers. Since then IBM itself, and other makers including Apple,Sinclair, and so forth, kept on developing more and more advancedversions of personal computers along with bigger and more powerful

ones like Mainframe and Supercomputers for more complicated works.

Meanwhile the tinier versions like laptops and even palmtops came upwith more advanced technologies over the past couple of decades. But

only advancement of technology cannot take the full credit for theamazing advancement of computers over the past few decades.


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Software, or the inbuilt logic to run the computer the way you like, kept

on being developed at an equal pace. The coming of famous softwaremanufacturers like Microsoft, Oracle, Sun have helped pacing up the

development. The result of all these painstaking research is to add toour ease in solving complex problems at a lightning speed with a device

that is easy to use and operate, called computer.

Dated: Feb. 21, 2006

Related Categories

PHP

SQLBy Donald W. Hyatt

Inserting a New Table Entry

For the examples we have been using in this tutorial, we are using an account called

games in which there is a table called scores for keeping track of high scores. The tablewas initialized from a file, but now we are going to add a new player in interactive mode.

We will use the MySQL command called INSERT INTO to select the table and

operation, and then the command SET to specify the value of any variables that we wishto initialize. In order to add a new player called "Richard", we will use the following

syntax:

mysql> INSERT INTO scores SET Name="Richard";Query OK, 1 row affected (0.00 sec)

Let's see the current values in the table scores.

mysql> SELECT * FROM scores;+---------+------+

| Name | Num |

+---------+------+

| Phyllis | 987 |

| Randy | 1285 |

| Don | 919 |

| Mark | 0 |

| Mary | 567 |

| Bob | 23 || Pete | 456 |

| Sally | 333 |

| Richard | NULL |

+---------+------+

9 rows in set (0.00 sec)

It is important to note that if a variable is a "PRIMARY KEY" or is specified in the initial

table creation as being something "NOT NULL", a value mustbe supplied at the time the
http://www.techiwarehouse.com/cat/31/PHPhttp://www.techiwarehouse.com/cat/33/SQLhttp://www.techiwarehouse.com/cat/31/PHPhttp://www.techiwarehouse.com/cat/33/SQL


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entry is inserted. Notice that Richard does not have a score at this time, so his score is not

0 but NULL instead.

Updating Information

Since Richard does not have a score at this time, let's take a look at the syntax to changethe information in a table. We will use the command UPDATE to identify the type ofaction and the table being used, and then the operation SET to assign a value to a variable

as well as WHERE to establish the criteria for updating the record. The systax for that

command would be:mysql> UPDATE scores SET Num=0 WHERE Name="Richard";Query OK, 1 row affected (0.00 sec)

Rows matched: 1 Changed: 1 Warnings: 0

mysql> SELECT * FROM scores WHERE Num=0;Query OK, 1 row affected (0.00 sec)


Now Richard's score is also zero. Of course, we could have created Richard's entry and

assigned the initial score to zero during the insert operation by doing the followingcommand instead:

mysql> INSERT INTO scores SET Name="Richard", Num=0;

We can even change one of the user's names. Let's suppose that Mary actually should becalled Marianne. We can change that entry for the name in the following way:

mysql> UPDATE scores SET Name="Marianne" WHERE Name="Mary";Query OK, 1 row affected (0.00 sec)


+----------+------+

| Name | Num |+----------+------+

| Phyllis | 987 |

| Randy | 1385 |

| Don | 919 |

| Mark | 0 |

| Marianne | 567 |

| Bob | 23 |

| Pete | 456 |

| Sally | 333 |

| Richard | 100 |

+----------+------+


Now let's try a slightly more sophisticated update operation. Suppose we wish to give 100Bonus points to the score of anyone whose name begins with an "R", such as in "Randy"

and "Richard". We could update each row separately by replacing their scores with the

appropriate values, but the following approach is a bit better. We will use the command

LIKE which permits us to have match of some value such as the leading "R" in both

names, and use the wildcardcharacter "%" to match the rest. We will then allow MySQL


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to do the arithmetic by adding 100 points to the old value of Num for any of those that

match. The syntax for that command is:

mysql> UPDATE scores SET Num=Num+100 WHERE Name LIKE "R%";Query OK, 1 row affected (0.00 sec)


+----------+------+| Name | Num |

+----------+------+

| Phyllis | 987 |

| Randy | 1385 |

| Don | 919 |

| Mark | 0 |

| Marianne | 567 |

| Bob | 23 |

| Pete | 456 |

| Sally | 333 |

| Richard | 100 |

+----------+------+


Now both scores have been changed.

Deleting a Table Entry

Now that we can add entries to the table, it will be important to learn how to delete them,

too. The command for removing something from a table is DELETE FROM to specifythe action and table, and then WHERE to indicate the criteria for deletion. If we desire to

delete Markfrom the table, the command would be:

mysql> DELETE FROM scores WHERE Name="Mark";Query OK, 1 row affected (0.00 sec)

Let's see the current values in the table scores.

+----------+------+

| Name | Num |

+----------+------+

| Phyllis | 987 |

| Randy | 1385 |

| Don | 919 |

| Marianne | 567 |

| Bob | 23 |

| Pete | 456 |

| Sally | 333 |

| Richard | 100 |

+----------+------+


If we add another user back to the table, MySQL apparently puts it in the empty slot it

has because Mark has been deleted.

mysql> INSERT INTO scores SET Name="Marty", Num=0;Query OK, 1 row affected (0.00 sec)

+----------+------+

| Name | Num |

+----------+------+


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| Phyllis | 987 |

| Randy | 1385 |

| Don | 919 |

| Marty | 0 |

| Marianne | 567 |

| Bob | 23 |

| Pete | 456 |

| Sally | 333 |

| Richard | 100 |

+----------+------+


ModifyingTable Attributes

Occasionally, it becomes necessary to change the attributes of one of the variables or

columns in a table. This is a frequent situation for a variable that might be declared

VARCHAR(20) lets say, and then the user wants to add something that might be 25

characters in length. Rather than destroying the entire table and starting from scratch, thismodification can be done using the MySQL command, ALTER TABLE combined with

the MODIFY command.

Before we modify a column or a field entry, lets take a look at how the fields arecurrently defined using the SHOW command:

mysql> SHOW FIELDS FROM scores;+-------+-------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| Name | varchar(20) | YES | | NULL | |

| Num | int(5) | YES | | NULL | |+-------+-------------+------+-----+---------+-------+


Now to change the Name variable from 20 to 25 characters, the command would be:

mysql> ALTER TABLE scores MODIFY Name VARCHAR(25);Query OK, 9 rows affected (0.02 sec)

Records: 9 Duplicates: 0 Warnings: 0

Let's see how the values have changed:+-------+-------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| Name | varchar(25) | YES | | NULL | |

| Num | int(5) | YES | | NULL | |

+-------+-------------+------+-----+---------+-------+2 rows in set (0.00 sec)

There are very sophisticated queries and updates that can be done with MySQL. It ispossible to add new columns to existing tables and even merge two databases into one

large table. Please check out the documentation at the MySQL website for more

information.


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MySQL: www.mysql.com
http://www.mysql.com/http://www.mysql.com/

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