Reason #10 - Most Of Your Accomplishments Are Invisible
The computer guy never hears anyone tell him, “I just want to let you know … everything is working fine!”
The reality is that people call the computer guy when something is wrong.
As a computer guy, if you work really hard to make everything work the way that it should, and things work fine, then people believe you don’t do anything. Everything you manage to get working correctly or do perfectly will forever remain unnoticed by computer users. They’ll only ever notice that you do anything when something isn’t working correctly, and you are called upon to fix it.
Reason #9 - Every Conversation You Have Is Roughly The Same
When the computer guy dares to mention what he does for a living, the typical response is, “I have a question about my home computer…”
Or when the computer guy first hears about a widespread problem within the computer network he’s responsible for, he can barely begin to assess the problem before a dozen other people call to report the same problem.
Or when the computer guy explains a certain process on a computer to a user who is incapable of retaining the process, he will inevitably need to reinstruct the user of this same process - indefinitely.
Reason #8 - You’re An Expert Of Bleeding-Edge Technology Products, Aren’t You?
The computer guy often finds himself in situations where someone is asking him for advice on a pending investment of the technological variety.
“I heard about (some hardware or software product) that can do (something desirable) for me. I brought you these (advertisements/reviews/printouts) because I wanted your recommendation. Which would you buy?”
Although the inquiring person sincerely trusts the computer guy’s judgment over their own, in almost every instance the real objective of these meetings is to ensure their own immunity from making a risky purchase.
If it turns out to be a bad investment, and they cannot get (the hardware or software product) to do (anything desirable), then you will be their personal scapegoat - “But honey, the computer guy said I should buy it!”
Reason #7 - Your Talents Are Forcibly Undervalued
Thanks to the constantly declining price of new computers, the computer guy cannot charge labor sums without a dispute. If he asks to be paid what he is worth, he will likely be met with the “why not buy new?” argument.
That is, desktop computers are always getting smaller, faster, and cheaper. It’s possible to purchase a new desktop computer for under $400. If the computer guy spends five hours fixing a computer and wants $100/hour for his time, his customer will be outraged, exclaiming “I didn’t even spend this much to BUY the computer, why should I pay this much just to FIX it?”
Reason #6 - You’re Never Allowed A Moment’s Peace
The computer guy is so prone to interruption that he rarely finds an opportunity to work on his own problems. This is because:
1. Computers never sleep.
2. Computer problems aren’t scheduled.
3. Every problem takes time to diagnose.
4. The computer guy can only give one problem his full attention.
5. Each user believes their problem deserves attention now.
Consequently, the computer guy has a 24/7 obligation to keep critical computer systems running, while simultaneously juggling everyone’s problems. He’ll often need to forfeit any opportunities to tend to his own needs for the sake of others - because at any moment, of any day, he can be interrupted by someone who wants to make their problem his problem.
Reason #5 - People Ask You To Perform Miracles
The computer guy is often mistaken for someone who possesses the combined skills of an old priest and a young priest. I’ll sum this up easily by example:
“No, I really can’t recover any files from your thumb drive, even if you did find it after it passed through your dog.”
Reason #4 - Your Assumed “All-Knowing” Status Sets You Up To Let People Down
There is no common understanding that there are smaller divisions within the computer industry, and that the computer guy cannot be an expert in all areas. What makes things worse, is when the computer guy attempts to explain this to someone asking for help, the person will often believe that the computer guy is withholding the desired knowledge to avoid having to help.
This is somewhat related to the next reason:
Reason #3 - You Possess Unlimited Responsibility
The computer guy is expected to solve problems. It is difficult to determine the boundaries of that expectation.
Some of the oddest things that I’ve been asked to do include:
1. Use pirated software to undelete important company files.
2. Create an Intranet, after explaining I didn’t know how to.
3. Teach someone how to hide their pornography collection.
Solving problems can range from replacing batteries in a wireless keyboard to investigating why the entire building loses power at the same time every morning. Resolutions can necessitate weaving a 50-foot cable through a drop ceiling, or wriggling under a house on your belly to add an electrical outlet.
Reasons #4 and #3 boil down to this: no matter how often you want to play the role of a hero, there will always be circumstances that test the limits of your ability to be one. It’s difficult to judge when helping someone means doing something immoral, and it’s even harder to admit you are unable to solve someone’s problem - and chances are, that someone will view you as incompetent because you were unable to help them.
Reason #2 - A Life Of Alienation
People only talk to the computer guy when they need him to fix something. Also, when the computer guy approaches a user, they’ll hop up out of their chair under the presumption that he’s there to fix something - as if it would never be expected that he only wants to strike up a conversation.
The fact that the computer guy never gets a moment’s peace can also practically force him to withdraw into solitude. His co-workers don’t understand that he doesn’t want to hear about their computer problems during his lunch hour - he does that every other hour of the day. That’s why the computer guy eats lunch alone with his door closed, or goes out to eat every day - not because he’s unfriendly, but because he needs to escape the incessant interruptions.
Reason #1 - You Have No Identity
It’s an awful experience when the computer guy shows up at a neighbor’s doorstep with a plate of Christmas cookies, only to have the child who answered the door call out, “Mom, the computer guy is here!” He begs for an identity that is not directly associated with computers, but “the computer guy” label walks ahead of him - it simply cannot be avoided. I was given a name and I’d love to be addressed by it.
Having read these reasons, you may believe that I’m complaining. It’s true that I was upset with many aspects of my life as the computer guy, but I’m past the point of complaining.
I took a good hard look at my existence and realized that things were not likely to change in the line of work I had chosen. Instead of just complaining, I took action and began making positive changes in my life.
Working in the computer industry isn’t for everybody. It wasn’t for me. I’ve compiled my reasons for putting it behind me and placed them here, so that anyone who is unsatisfied with their life working in computers might recognize it’s not for them either.
Thursday, January 31, 2008
History Of Computers
While computers are now an important part of the lives of human beings, there was a time where computers did not exist. Knowing the history of computers and how much progression has been made can help you understand just how complicated and innovative the creation of computers really is.
Unlike most devices, the computer is one of the few inventions that does not have one specific inventor. Throughout the development of the computer, many people have added their creations to the list required to make a computer work. Some of the inventions have been different types of computers, and some of them were parts required to allow computers to be developed further.
The Beginning
Perhaps the most significant date in the history of computers is the year 1936. It was in this year that the first “computer” was developed. It was created by Konrad Zuse and dubbed the Z1 Computer. This computer stands as the first as it was the first system to be fully programmable. There were devices prior to this, but none had the computing power that sets it apart from other electronics.
It wasn’t until 1942 that any business saw profit and opportunity in computers. This first company was called ABC computers, owned and operated by John Atanasoff and Clifford Berry. Two years later, the Harvard Mark I computer was developed, furthering the science of computing.
Over the course of the next few years, inventors all over the world began to search more into the study of computers, and how to improve upon them. Those next ten years say the introduction of the transistor, which would become a vital part of the inner workings of the computer, the ENIAC 1 computer, as well as many other types of systems. The ENIAC 1 is perhaps one of the most interesting, as it required 20,000 vacuum tubes to operate. It was a massive machine, and started the revolution to build smaller and faster computers.
The age of computers was forever altered by the introduction of International Business Machines, or IBM, into the computing industry in 1953. This company, over the course of computer history, has been a major player in the development of new systems and servers for public and private use. This introduction brought about the first real signs of competition within computing history, which helped to spur faster and better development of computers. Their first contribution was the IBM 701 EDPM Computer.
A Programming Language Evolves
A year later, the first successful high level programming language was created. This was a programming language not written in ‘assembly’ or binary, which are considered very low level languages. FORTRAN was written so that more people could begin to program computers easily.
The year 1955, the Bank of America, coupled with Stanford Research Institute and General Electric, saw the creation of the first computers for use in banks. The MICR, or Magnetic Ink Character Recognition, coupled with the actual computer, the ERMA, was a breakthrough for the banking industry. It wasn’t until 1959 that the pair of systems were put into use in actual banks.
During 1958, one of the most important breakthroughs in computer history occurred, the creation of the integrated circuit. This device, also known as the chip, is one of the base requirements for modern computer systems. On every motherboard and card within a computer system, are many chips that contain information on what the boards and cards do. Without these chips, the systems as we know them today cannot function.
Gaming, Mice, & the Internet
For many computer users now, games are a vital part of the computing experience. 1962 saw the creation of the first computer game, which was created by Steve Russel and MIT, which was dubbed Spacewar.
The mouse, one of the most basic components of modern computers, was created in 1964 by Douglass Engelbart. It obtained its name from the “tail” leading out of the device.
One of the most important aspects of computers today was invented in 1969. ARPA net was the original Internet, which provided the foundation for the Internet that we know today. This development would result in the evolution of knowledge and business across the entire planet.
It wasn’t until 1970 that Intel entered the scene with the first dynamic RAM chip, which resulted in an explosion of computer science innovation.
On the heels of the RAM chip was the first microprocessor, which was also designed by Intel. These two components, in addition to the chip developed in 1958, would number among the core components of modern computers.
A year later, the floppy disk was created, gaining its name from the flexibility of the storage unit. This was the first step in allowing most people to transfer bits of data between unconnected computers.
The first networking card was created in 1973, allowing data transfer between connected computers. This is similar to the Internet, but allows for the computers to connect without use of the Internet.
Household PC’s Emerge
The next three years were very important for computers. This is when companies began to develop systems for the average consumer. The Scelbi, Mark-8 Altair, IBM 5100, Apple I and II, TRS-80, and the Commodore Pet computers were the forerunners in this area. While expensive, these machines started the trend for computers within common households.
One of the most major breathroughs in computer software occurred in 1978 with the release of the VisiCalc Spreadsheet program. All development costs were paid for within a two week period of time, which makes this one of the most successful programs in computer history.
1979 was perhaps one of the most important years for the home computer user. This is the year that WordStar, the first word processing program, was released to the public for sale. This drastically altered the usefulness of computers for the everyday user.
The IBM Home computer quickly helped revolutionize the consumer market in 1981, as it was affordable for home owners and standard consumers. 1981 also saw the the mega-giant Microsoft enter the scene with the MS-DOS operating system. This operating system utterly changed computing forever, as it was easy enough for everyone to learn.
The Competition Begins : Apple vs. Microsoft
Computers saw yet another vital change during the year of 1983. The Apple Lisa computer was the first with a graphical user interface, or a GUI. Most modern programs contain a GUI, which allows them to be easy to use and pleasing for the eyes. This marked the beginning of the out dating of most text based only programs.
Beyond this point in computer history, many changes and alterations have occurred, from the Apple-Microsoft wars, to the developing of microcomputers and a variety of computer breakthroughs that have become an accepted part of our daily lives. Without the initial first steps of computer history, none of this would have been possible.
Source: http://www.nonstopmasti.be/?p=
Unlike most devices, the computer is one of the few inventions that does not have one specific inventor. Throughout the development of the computer, many people have added their creations to the list required to make a computer work. Some of the inventions have been different types of computers, and some of them were parts required to allow computers to be developed further.
The Beginning
Perhaps the most significant date in the history of computers is the year 1936. It was in this year that the first “computer” was developed. It was created by Konrad Zuse and dubbed the Z1 Computer. This computer stands as the first as it was the first system to be fully programmable. There were devices prior to this, but none had the computing power that sets it apart from other electronics.
It wasn’t until 1942 that any business saw profit and opportunity in computers. This first company was called ABC computers, owned and operated by John Atanasoff and Clifford Berry. Two years later, the Harvard Mark I computer was developed, furthering the science of computing.
Over the course of the next few years, inventors all over the world began to search more into the study of computers, and how to improve upon them. Those next ten years say the introduction of the transistor, which would become a vital part of the inner workings of the computer, the ENIAC 1 computer, as well as many other types of systems. The ENIAC 1 is perhaps one of the most interesting, as it required 20,000 vacuum tubes to operate. It was a massive machine, and started the revolution to build smaller and faster computers.
The age of computers was forever altered by the introduction of International Business Machines, or IBM, into the computing industry in 1953. This company, over the course of computer history, has been a major player in the development of new systems and servers for public and private use. This introduction brought about the first real signs of competition within computing history, which helped to spur faster and better development of computers. Their first contribution was the IBM 701 EDPM Computer.
A Programming Language Evolves
A year later, the first successful high level programming language was created. This was a programming language not written in ‘assembly’ or binary, which are considered very low level languages. FORTRAN was written so that more people could begin to program computers easily.
The year 1955, the Bank of America, coupled with Stanford Research Institute and General Electric, saw the creation of the first computers for use in banks. The MICR, or Magnetic Ink Character Recognition, coupled with the actual computer, the ERMA, was a breakthrough for the banking industry. It wasn’t until 1959 that the pair of systems were put into use in actual banks.
During 1958, one of the most important breakthroughs in computer history occurred, the creation of the integrated circuit. This device, also known as the chip, is one of the base requirements for modern computer systems. On every motherboard and card within a computer system, are many chips that contain information on what the boards and cards do. Without these chips, the systems as we know them today cannot function.
Gaming, Mice, & the Internet
For many computer users now, games are a vital part of the computing experience. 1962 saw the creation of the first computer game, which was created by Steve Russel and MIT, which was dubbed Spacewar.
The mouse, one of the most basic components of modern computers, was created in 1964 by Douglass Engelbart. It obtained its name from the “tail” leading out of the device.
One of the most important aspects of computers today was invented in 1969. ARPA net was the original Internet, which provided the foundation for the Internet that we know today. This development would result in the evolution of knowledge and business across the entire planet.
It wasn’t until 1970 that Intel entered the scene with the first dynamic RAM chip, which resulted in an explosion of computer science innovation.
On the heels of the RAM chip was the first microprocessor, which was also designed by Intel. These two components, in addition to the chip developed in 1958, would number among the core components of modern computers.
A year later, the floppy disk was created, gaining its name from the flexibility of the storage unit. This was the first step in allowing most people to transfer bits of data between unconnected computers.
The first networking card was created in 1973, allowing data transfer between connected computers. This is similar to the Internet, but allows for the computers to connect without use of the Internet.
Household PC’s Emerge
The next three years were very important for computers. This is when companies began to develop systems for the average consumer. The Scelbi, Mark-8 Altair, IBM 5100, Apple I and II, TRS-80, and the Commodore Pet computers were the forerunners in this area. While expensive, these machines started the trend for computers within common households.
One of the most major breathroughs in computer software occurred in 1978 with the release of the VisiCalc Spreadsheet program. All development costs were paid for within a two week period of time, which makes this one of the most successful programs in computer history.
1979 was perhaps one of the most important years for the home computer user. This is the year that WordStar, the first word processing program, was released to the public for sale. This drastically altered the usefulness of computers for the everyday user.
The IBM Home computer quickly helped revolutionize the consumer market in 1981, as it was affordable for home owners and standard consumers. 1981 also saw the the mega-giant Microsoft enter the scene with the MS-DOS operating system. This operating system utterly changed computing forever, as it was easy enough for everyone to learn.
The Competition Begins : Apple vs. Microsoft
Computers saw yet another vital change during the year of 1983. The Apple Lisa computer was the first with a graphical user interface, or a GUI. Most modern programs contain a GUI, which allows them to be easy to use and pleasing for the eyes. This marked the beginning of the out dating of most text based only programs.
Beyond this point in computer history, many changes and alterations have occurred, from the Apple-Microsoft wars, to the developing of microcomputers and a variety of computer breakthroughs that have become an accepted part of our daily lives. Without the initial first steps of computer history, none of this would have been possible.
Source: http://www.nonstopmasti.be/?p=
Thursday, January 24, 2008
Computers
Computers are the future whether we like it or not. Some people dislike computers, because of the complications it takes to understand the basics. Computers are not exactly the easiest tools to work with, but they are the most rewarding, and they are the future.
Future cars will all be run by computer. You will be able to talk to a car and it will take you to your destination. Telephones are technically computerized. You will soon be able to talk to a person on the telephone as well as look at the person you are talking to on a television set. Also television is computerized. Soon we will have true three dimensional television. We will be able to watch television like we never have watched it before. We will be able to touch the characters, and feel the characters like they were in the room with you.
For people who don't know much about computers, you will be lost in the future. You should learn what you can while you still have the chance, because things will develop too quickly for you and you will not be able to cope with new technological events. Computers will fall into careers and our everyday life more rapidly then you think.
Perhaps you would like to be a teacher. You will store all class data, students work, names, grades, records all accessible by computer. Or, how about a doctor. You will use computers to examine and evaluate a patients problem quicker and more efficiently. These are only a few examples. The bottom line is, computers provide worthwhile careers.
Having a job that involves computers, in terms of the conditions, is very much similar to any office job. In most of the common jobs, the worker will get to an office in the morning, sit at a desk, in front of a computer, and will do very little manual labor except a lot of typing. For example, the computer consultant we have already mentioned, might do several jobs, a few being: Traveling to clients computers, writing customized programs, repairing computer parts, and teaching/ guiding students in learning. Only the repair aspect of this job, would require actual manual labor. However, computers and computer parts are so well built and shall continue to be even more well built, that repair is only a small fraction of a consultant's daily routines. Overall, conditions for the majority of jobs dealing mainly with computers, shall include very little manual labor, unfavorable conditions, and much knowledge, typing skills, and good communication skills in dealing with people.
With computers and the computer industry being the most rapidly changing industry and product in the world, the job outlook for any job dealing with computers or the industry is almost completly unpredictable. However, with the computer industry only being around for a short period of time compared to the other industries of the world, we can still get a somewhat accurate idea of where the industry is heading based on the amount of change already inccured by the technology.
Firstly, computers have, over the years, been taking control of more and more of the dealings of human everyday life, and because of efficiency they have proven, it would be likely to assume that one major change of the computer industry from today until tomorrow will be control of more and more of our everyday life. Therefore, the outlook on the jobs relating to computers in the future, shall be not only enlarged in field, but also will encompass more aspects of everyday life than anything before in history, except for maybe sleeping. By this, it is meant that computers will not just be something that you choose to know or learn in the future, but something that will just be part of everyone's common sense and knowledge. Because computers are so rapidly changing not only in their technology but also the amount of job fields they create, earnings is yet another difficult aspect of computers to predict.
As of now, because computer knowledge is so valuable in today's business world, salaries are quite favorable. This along with the job conditions mentioned earlier in this report contribute greatly to a desire of possessing computer knowledge. To give you an idea of a few of the actual jobs involving computers, and the salaries that they provide, one existing job, and the salary it provides will be discussed in detail. A computer programmer, one who designs programs (the directions for a computer to follow), usually will work for a company or a large cooperation in designing a program that will be specifically made for that business's applications. This would not only make the business more efficent, but also save lots of money for the business. The computer programmer is usually an independant contractor who chooses jobs he might enjoy doing. These programmers usually are paid between 200 and 800 dollars per hour for their time at their computer inventing these programs which will later run an entire business.
Computers, providing such a variety of different jobs, overlaps into many many other related occupations. Because of the astounding amount of parts computers play in job fields today, only two very different related occupations shall be discussed. A doctor 30 years ago depended greatly on his own accuracy in performing difficult surgery. However, today doctors rely greatly on computerized medical equipment programmed by computer programmers to operate on a patient. Computers are almost 50% more accurate than a doctor's own human skill, which allows for human error where computers are not human so this factor does not exist, hence making them that much more efficient. A car mechanic used to rely on an experienced ear to determine if a car was out of tune. However, in today's modern times, a mechanic can even deaf, and still more accurately determine whether a car is out of tune than that same mechanic who might even have 50 years experience. Again, the reason - computers. Now most modern mechanic shops have in use, highly sophisticated machines which run soley on computers to determine a car's status, simply by being hooked up to a car's exhaust pipe, thus eliminating having to remove any parts of the car, thus not only providing more efficiency, but also saving time in putting parts back on a car.
Computers, being highly sophisticated tools, accordingly are difficult to learn and even more so when a person has had no exposure to them in the past. Many computer courses are being offered to cover the many professions that computers rule. Also if one was desirous of entering the computer job field, it would be highly recommended that the person started taking classes on computers as early as possible, as the younger you are the more simple it is to learn something unfamiliar.
Future cars will all be run by computer. You will be able to talk to a car and it will take you to your destination. Telephones are technically computerized. You will soon be able to talk to a person on the telephone as well as look at the person you are talking to on a television set. Also television is computerized. Soon we will have true three dimensional television. We will be able to watch television like we never have watched it before. We will be able to touch the characters, and feel the characters like they were in the room with you.
For people who don't know much about computers, you will be lost in the future. You should learn what you can while you still have the chance, because things will develop too quickly for you and you will not be able to cope with new technological events. Computers will fall into careers and our everyday life more rapidly then you think.
Perhaps you would like to be a teacher. You will store all class data, students work, names, grades, records all accessible by computer. Or, how about a doctor. You will use computers to examine and evaluate a patients problem quicker and more efficiently. These are only a few examples. The bottom line is, computers provide worthwhile careers.
Having a job that involves computers, in terms of the conditions, is very much similar to any office job. In most of the common jobs, the worker will get to an office in the morning, sit at a desk, in front of a computer, and will do very little manual labor except a lot of typing. For example, the computer consultant we have already mentioned, might do several jobs, a few being: Traveling to clients computers, writing customized programs, repairing computer parts, and teaching/ guiding students in learning. Only the repair aspect of this job, would require actual manual labor. However, computers and computer parts are so well built and shall continue to be even more well built, that repair is only a small fraction of a consultant's daily routines. Overall, conditions for the majority of jobs dealing mainly with computers, shall include very little manual labor, unfavorable conditions, and much knowledge, typing skills, and good communication skills in dealing with people.
With computers and the computer industry being the most rapidly changing industry and product in the world, the job outlook for any job dealing with computers or the industry is almost completly unpredictable. However, with the computer industry only being around for a short period of time compared to the other industries of the world, we can still get a somewhat accurate idea of where the industry is heading based on the amount of change already inccured by the technology.
Firstly, computers have, over the years, been taking control of more and more of the dealings of human everyday life, and because of efficiency they have proven, it would be likely to assume that one major change of the computer industry from today until tomorrow will be control of more and more of our everyday life. Therefore, the outlook on the jobs relating to computers in the future, shall be not only enlarged in field, but also will encompass more aspects of everyday life than anything before in history, except for maybe sleeping. By this, it is meant that computers will not just be something that you choose to know or learn in the future, but something that will just be part of everyone's common sense and knowledge. Because computers are so rapidly changing not only in their technology but also the amount of job fields they create, earnings is yet another difficult aspect of computers to predict.
As of now, because computer knowledge is so valuable in today's business world, salaries are quite favorable. This along with the job conditions mentioned earlier in this report contribute greatly to a desire of possessing computer knowledge. To give you an idea of a few of the actual jobs involving computers, and the salaries that they provide, one existing job, and the salary it provides will be discussed in detail. A computer programmer, one who designs programs (the directions for a computer to follow), usually will work for a company or a large cooperation in designing a program that will be specifically made for that business's applications. This would not only make the business more efficent, but also save lots of money for the business. The computer programmer is usually an independant contractor who chooses jobs he might enjoy doing. These programmers usually are paid between 200 and 800 dollars per hour for their time at their computer inventing these programs which will later run an entire business.
Computers, providing such a variety of different jobs, overlaps into many many other related occupations. Because of the astounding amount of parts computers play in job fields today, only two very different related occupations shall be discussed. A doctor 30 years ago depended greatly on his own accuracy in performing difficult surgery. However, today doctors rely greatly on computerized medical equipment programmed by computer programmers to operate on a patient. Computers are almost 50% more accurate than a doctor's own human skill, which allows for human error where computers are not human so this factor does not exist, hence making them that much more efficient. A car mechanic used to rely on an experienced ear to determine if a car was out of tune. However, in today's modern times, a mechanic can even deaf, and still more accurately determine whether a car is out of tune than that same mechanic who might even have 50 years experience. Again, the reason - computers. Now most modern mechanic shops have in use, highly sophisticated machines which run soley on computers to determine a car's status, simply by being hooked up to a car's exhaust pipe, thus eliminating having to remove any parts of the car, thus not only providing more efficiency, but also saving time in putting parts back on a car.
Computers, being highly sophisticated tools, accordingly are difficult to learn and even more so when a person has had no exposure to them in the past. Many computer courses are being offered to cover the many professions that computers rule. Also if one was desirous of entering the computer job field, it would be highly recommended that the person started taking classes on computers as early as possible, as the younger you are the more simple it is to learn something unfamiliar.
computer and technology
By the year 2010, scientists predict we will be immersed in a sea of miniature computers.
Current portable computing systems are cumbersome
Many of us carry three or four digital devices with us, according to Simon Moore of Cambridge University's Computer Laboratory, but soon that figure will be in the hundreds.
"They'll be woven into our clothing as identification markers during manufacture," he said.
"They might tell your washing machine what cycle to use, or monitor bio-signs to alert us to impending illness."
Those predictions came at the launch of the Cambridge-MIT Institute's Pervasive Computing initiative (CMI).
It is part of a transatlantic collaboration between information scientists and engineers at Cambridge University and the Massachusetts Institute of Technology in Boston.
Intelligent agents
As well as ensuring the health of us and our clothes, those ubiquitous digital devices will, by default, be communicators. They will talk to each other and us, wherever we are.
Hot-desking may have been a big trend in the nineties, but future computer users will be truly nomadic, able to access information everywhere.
We have this joke that we want to make computers as pervasive and as unobtrusive as oxygen
Umar Saif, MIT
The challenge for CMI researchers is to build immersive systems that automatically reconfigure data or voice call connections between the full range of digital devices, without getting cut off.
Keeping such systems secure from unauthorised use and attack, will be crucial, as will be the inclusion of intelligent filters that prevent the system pestering us with trivia.
This became patently clear last year when MIT tested a prototype system which monitored a person's location and, seamlessly, used the best available communications device to reach them.
A cell phone call turned into a video-conference call when the researcher entered his office and back to a cell phone call as he left for his car.
But the embryonic system noticed a problem with the researcher's office computer, according to MIT's Umar Saif.
"You couldn't escape from the system", he told Go Digital. "It would find whatever communications that was available and call you.
"The computer was just trying to be helpful, but it turned into the nightmare scenario because there was no way of shutting the system down".
Accessible information
Such pestering from not-so intelligent computer systems in the future will be a real turn-off for users, according to Lancaster University's Professor of Organisational Psychology, Cary Cooper.
"People already suffer from technological overload and it's our fault because we allow the technology to manage us, not the other way around," he said.
Too much information can be overwhelming
"Some of the problems we have are because technologies are created by engineers trying to think of a really interesting tweak.
"Let the e-mail chase the cell phone if someone's away on business and if we can't get him that way, we'll get him some other way.
"But they should think more about the impact of these developments on our lives."
This is what the CMI researchers will be doing, said Dr Saif.
Ultimately, he said, the issue is not about information overload but making the power of computers more accessible to ordinary people with no special skills and with little money to shell out on the kinds of gadgets we rely on today.
Energy efficient processors running on wireless devices with vastly increased battery time will be essential to the CMI's pervasive computing vision, as will enhancements in computer vision and speech processing.
"We have this joke that we want to make computers as pervasive and as unobtrusive as oxygen", he said.
"We want people to use computers without even realising they're using them."
This article is about the machine. For the magazine, see Computer (magazine).
The NASA Columbia Supercomputer.
A computer in a wristwatch.
A computer is a programmable device, usually electronic in nature, that can store, retrieve, and process data.[1] The first programmable electronic computers date to the mid-20th century (around 1940 - 1941), although the concept and various non-electronic and analog models date back before this. Early electronic computers were the size of a large room, and their thermionic valve technology demanded huge amounts of power.[2] Today, computers are based upon tiny integrated circuits, are hundreds of millions to hundreds of billions of times more powerful,[3] and simpler computers can be made small enough to fit into a wrist watch and powered by a simple watch battery.
Personal computers and their portable equivalent, the laptop computer, have come to be an integral part of the modern information age; they are what most people think of as "a computer". However, the most common form of computer in use today is by far the embedded computer. Embedded computers are small, simple devices that are often used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, consumer electronics, kitchen and other domestic appliances, hi fi components, cars and other vehicles, medical devices such as hearing aids, mobile phones, and children's toys.
The ability to store and execute programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: Any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks as long as time and storage capacity are not considerations.
Contents
[hide]
1 History of computing
2 Stored program architecture
2.1 Programs
2.2 Example
3 How computers work
3.1 Control unit
3.2 Arithmetic/logic unit (ALU)
3.3 Memory
3.4 Input/output (I/O)
3.5 Multitasking
3.6 Multiprocessing
3.7 Networking and the Internet
4 Further topics
4.1 Hardware
4.2 Software
4.3 Programming languages
4.4 Professions and organizations
5 See also
6 Notes
7 References
[edit] History of computing
Main article: History of computing
The Jacquard loom was one of the first programmable devices.
It is difficult to define any one device as the earliest computer. The very definition of a computer has changed and it is therefore impossible to identify the first computer. Many devices once called "computers" would no longer qualify as such by today's standards.
Originally, the term "computer" referred to a person who performed numerical calculations (a human computer), often with the aid of a mechanical calculating device. Examples of early mechanical computing devices included the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism (which dates from about 150-100 BC). The end of the Middle Ages saw a re-invigoration of European mathematics and engineering, and Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers.
However, none of those devices fit the modern definition of a computer because they could not be programmed. In 1801, Joseph Marie Jacquard made an improvement to the textile loom that used a series of punched paper cards as a template to allow his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability.
In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer that he called "The Analytical Engine".[4] Due to limited finance, and an inability to resist tinkering with the design, Babbage never actually built his Analytical Engine.[2]
Large-scale automated data processing of punched cards was performed for the US Census in 1890 by tabulating machines designed by Herman Hollerith and manufactured by the Computing Tabulating Recording Corporation, which later became IBM. By the end of the 19th century a number of technologies that would later prove useful in the realization of practical computers had begun to appear: the punched card, Boolean algebra, the vacuum tube (thermionic valve) and the teleprinter.
During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers.
Defining characteristics of five first operative digital computers Computer Shown working Binary Electronic Programmable Turing complete
Zuse Z3 May 1941 Yes No By punched film stock Yes (1998)
Atanasoff–Berry Computer Summer 1941 Yes Yes No No
Colossus December 1943 / January 1944 Yes Yes Partially, by rewiring No
Harvard Mark I – IBM ASCC 1944 No No By punched paper tape Yes (1998)
ENIAC 1944 No Yes Partially, by rewiring Yes
1948 No Yes By Function Table ROM Yes
A succession of steadily more powerful and flexible computing devices were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by Claude Shannon in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as "the first digital electronic computer" is difficult (Shannon 1940). Notable achievements include:
EDSAC was one of the first computers to implement the stored program (von Neumann) architecture.
Konrad Zuse's electromechanical "Z machines". The Z3 (1941) was the first working machine featuring binary arithmetic, including floating point arithmetic and a measure of programmability. In 1998 the Z3 was proved to be Turing complete, therefore being the world's first operational computer.
The non-programmable Atanasoff–Berry Computer (1941) which used vacuum tube based computation, binary numbers, and regenerative capacitor memory.
The secret British Colossus computer (1944), which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for breaking German wartime codes.
The Harvard Mark I (1944), a large-scale electromechanical computer with limited programmability.
The US Army's Ballistics Research Laboratory ENIAC (1946), which used decimal arithmetic and is sometimes called the first general purpose electronic computer (since Konrad Zuse's Z3 of 1941 used electromagnets instead of electronics). Initially, however, ENIAC had an inflexible architecture which essentially required rewiring to change its programming.
Several developers of ENIAC, recognizing its flaws, came up with a far more flexible and elegant design, which came to be known as the stored program architecture or von Neumann architecture. This design was first formally described by John von Neumann in the paper "First Draft of a Report on the EDVAC", published in 1945. A number of projects to develop computers based on the stored program architecture commenced around this time, the first of these being completed in Great Britain. The first to be demonstrated working was the Manchester Small-Scale Experimental Machine (SSEM) or "Baby". However, the EDSAC, completed a year after SSEM, was perhaps the first practical implementation of the stored program design. Shortly thereafter, the machine originally described by von Neumann's paper—EDVAC—was completed but did not see full-time use for an additional two years.
Nearly all modern computers implement some form of the stored program architecture, making it the single trait by which the word "computer" is now defined. By this standard, many earlier devices would no longer be called computers by today's definition, but are usually referred to as such in their historical context. While the technologies used in computers have changed dramatically since the first electronic, general-purpose computers of the 1940s, most still use the von Neumann architecture. The design made the universal computer a practical reality.
Microprocessors are miniaturized devices that often implement stored program CPUs.
Vacuum tube-based computers were in use throughout the 1950s, but were largely replaced in the 1960s by transistor-based devices, which were smaller, faster, cheaper, used less power and were more reliable. These factors allowed computers to be produced on an unprecedented commercial scale. By the 1970s, the adoption of integrated circuit technology and the subsequent creation of microprocessors such as the Intel 4004 caused another leap in size, speed, cost and reliability. By the 1980s, computers had become sufficiently small and cheap to replace simple mechanical controls in domestic appliances such as washing machines. Around the same time, computers became widely accessible for personal use by individuals in the form of home computers and the now ubiquitous personal computer. In conjunction with the widespread growth of the Internet since the 1990s, personal computers are becoming as common as the television and the telephone and almost all modern electronic devices contain a computer of some kind.
[edit] Stored program architecture
Main articles: Computer program and Computer programming
The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. That is to say that a list of instructions (the program) can be given to the computer and it will store them and carry them out at some time in the future.
In most cases, computer instructions are simple: add one number to another, move some data from one location to another, send a message to some external device, etc. These instructions are read from the computer's memory and are generally carried out (executed) in the order they were given. However, there are usually specialized instructions to tell the computer to jump ahead or backwards to some other place in the program and to carry on executing from there. These are called "jump" instructions (or branches). Furthermore, jump instructions may be made to happen conditionally so that different sequences of instructions may be used depending on the result of some previous calculation or some external event. Many computers directly support subroutines by providing a type of jump that "remembers" the location it jumped from and another instruction to return to that point.
Program execution might be likened to reading a book. While a person will normally read each word and line in sequence, they may at times jump back to an earlier place in the text or skip sections that are not of interest. Similarly, a computer may sometimes go back and repeat the instructions in some section of the program over and over again until some internal condition is met. This is called the flow of control within the program and it is what allows the computer to perform tasks repeatedly without human intervention.
Comparatively, a person using a pocket calculator can perform a basic arithmetic operation such as adding two numbers with just a few button presses. But to add together all of the numbers from 1 to 1,000 would take thousands of button presses and a lot of time—with a near certainty of making a mistake. On the other hand, a computer may be programmed to do this with just a few simple instructions. For example:
mov #0,sum ; set sum to 0 mov #1,num ; set num to 1 loop: add num,sum ; add num to sum add #1,num ; add 1 to num cmp num,#1000 ; compare num to 1000 ble loop ; if num <= 1000, go back to 'loop' halt ; end of program. stop running Once told to run this program, the computer will perform the repetitive addition task without further human intervention. It will almost never make a mistake and a modern PC can complete the task in about a millionth of a second.[5]
However, computers cannot "think" for themselves in the sense that they only solve problems in exactly the way they are programmed to. An intelligent human faced with the above addition task might soon realize that instead of actually adding up all the numbers one can simply use the equation
and arrive at the correct answer (500,500) with little work.[6] In other words, a computer programmed to add up the numbers one by one as in the example above would do exactly that without regard to efficiency or alternative solutions.
[edit] Programs
A 1970s punched card containing one line from a FORTRAN program. The card reads: "Z(1) = Y + W(1)" and is labelled "PROJ039" for identification purposes.
In practical terms, a computer program might include anywhere from a dozen instructions to many millions of instructions for something like a word processor or a web browser. A typical modern computer can execute billions of instructions every second and nearly never make a mistake over years of operation.
Large computer programs may take teams of computer programmers years to write and the probability of the entire program having been written completely in the manner intended is unlikely. Errors in computer programs are called bugs. Sometimes bugs are benign and do not affect the usefulness of the program, in other cases they might cause the program to completely fail (crash), in yet other cases there may be subtle problems. Sometimes otherwise benign bugs may be used for malicious intent, creating a security exploit. Bugs are usually not the fault of the computer. Since computers merely execute the instructions they are given, bugs are nearly always the result of programmer error or an oversight made in the program's design.[7]
In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). The command to add two numbers together would have one opcode, the command to multiply them would have a different opcode and so on. The simplest computers are able to perform any of a handful of different instructions, the more complex computers have several hundred to choose from—each with a unique numerical code. Since the computer's memory is able to store numbers, it can also store the instruction codes. This leads to the important fact that entire programs (which are just lists of instructions) can be represented as lists of numbers and can themselves be manipulated inside the computer just as if they were numeric data. The fundamental concept of storing programs in the computer's memory alongside the data they operate on is the crux of the von Neumann, or stored program, architecture. In some cases, a computer might store some or all of its program in memory that is kept separate from the data it operates on. This is called the Harvard architecture after the Harvard Mark I computer. Modern von Neumann computers display some traits of the Harvard architecture in their designs, such as in CPU caches.
While it is possible to write computer programs as long lists of numbers (machine language) and this technique was used with many early computers,[8] it is extremely tedious to do so in practice, especially for complicated programs. Instead, each basic instruction can be given a short name that is indicative of its function and easy to remember—a mnemonic such as ADD, SUB, MULT or JUMP. These mnemonics are collectively known as a computer's assembly language. Converting programs written in assembly language into something the computer can actually understand (machine language) is usually done by a computer program called an assembler. Machine languages and the assembly languages that represent them (collectively termed low-level programming languages) tend to be unique to a particular type of computer. For instance, an ARM architecture computer (such as may be found in a PDA or a hand-held videogame) cannot understand the machine language of an Intel Pentium or the AMD Athlon 64 computer that might be in a PC.[9]
Though considerably easier than in machine language, writing long programs in assembly language is often difficult and error prone. Therefore, most complicated programs are written in more abstract high-level programming languages that are able to express the needs of the computer programmer more conveniently (and thereby help reduce programmer error). High level languages are usually "compiled" into machine language (or sometimes into assembly language and then into machine language) using another computer program called a compiler.[10] Since high level languages are more abstract than assembly language, it is possible to use different compilers to translate the same high level language program into the machine language of many different types of computer. This is part of the means by which software like video games may be made available for different computer architectures such as personal computers and various video game consoles.
The task of developing large software systems is an immense intellectual effort. It has proven, historically, to be very difficult to produce software with an acceptably high reliability, on a predictable schedule and budget. The academic and professional discipline of software engineering concentrates specifically on this problem.
[edit] Example
A traffic light showing red.
Suppose a computer is being employed to drive a traffic light. A simple stored program might say:
Turn off all of the lights
Turn on the red light
Wait for sixty seconds
Turn off the red light
Turn on the green light
Wait for one minute
Turn off the green light
Turn on the yellow light
Wait for two seconds
Turn off the yellow light
Jump to instruction number (2)
With this set of instructions, the computer would cycle the light continually through red, green, yellow and back to red again until told to stop running the program.
However, suppose there is a simple on/off switch connected to the computer that is intended be used to make the light flash red while some maintenance operation is being performed. The program might then instruct the computer to:
Turn off all of the lights
Turn on the red light
Wait for sixty seconds
Turn off the red light
Turn on the green light
Wait for sixty seconds
Turn off the green light
Turn on the yellow light
Wait for two seconds
Turn off the yellow light
If the maintenance switch is NOT turned on then jump to instruction number 2
Turn on the red light
Wait for one second
Turn off the red light
Wait for one second
Jump to instruction number 11
In this manner, the computer is either running the instructions from number (2) to (11) over and over or its running the instructions from (11) down to (16) over and over, depending on the position of the switch.[11]
[edit] How computers work
Main articles: Central processing unit and Microprocessor
A general purpose computer has four main sections: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by busses, often made of groups of wires.
The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were comprised of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor.
[edit] Control unit
Main articles: CPU design and Control unit
The control unit (often called a control system or central controller) directs the various components of a computer. It reads and interprets (decodes) instructions in the program one by one. The control system decodes each instruction and turns it into a series of control signals that operate the other parts of the computer.[12] Control systems in advanced computers may change the order of some instructions so as to improve performance.
A key component common to all CPUs is the program counter, a special memory cell (a register) that keeps track of which location in memory the next instruction is to be read from.[13]
Diagram showing how a particular MIPS architecture instruction would be decoded by the control system.
The control system's function is as follows—note that this is a simplified description and some of these steps may be performed concurrently or in a different order depending on the type of CPU:
Read the code for the next instruction from the cell indicated by the program counter.
Decode the numerical code for the instruction into a set of commands or signals for each of the other systems.
Increment the program counter so it points to the next instruction.
Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code.
Provide the necessary data to an ALU or register.
If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation.
Write the result from the ALU back to a memory location or to a register or perhaps an output device.
Jump back to step (1).
Since the program counter is (conceptually) just another set of memory cells, it can be changed by calculations done in the ALU. Adding 100 to the program counter would cause the next instruction to be read from a place 100 locations further down the program. Instructions that modify the program counter are often known as "jumps" and allow for loops (instructions that are repeated by the computer) and often conditional instruction execution (both examples of control flow).
It is noticeable that the sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program - and indeed, in some more complex CPU designs, there is another yet smaller computer called a microsequencer that runs a microcode program that causes all of these events to happen.
[edit] Arithmetic/logic unit (ALU)
Main article: Arithmetic logic unit
The ALU is capable of performing two classes of operations: arithmetic and logic.
The set of arithmetic operations that a particular ALU supports may be limited to adding and subtracting or might include multiplying or dividing, trigonometry functions (sine, cosine, etc) and square roots. Some can only operate on whole numbers (integers) whilst others use floating point to represent real numbers—albeit with limited precision. However, any computer that is capable of performing just the simplest operations can be programmed to break down the more complex operations into simple steps that it can perform. Therefore, any computer can be programmed to perform any arithmetic operation—although it will take more time to do so if its ALU does not directly support the operation. An ALU may also compare numbers and return boolean truth values (true or false) depending on whether one is equal to, greater than or less than the other ("is 64 greater than 65?").
Logic operations involve Boolean logic: AND, OR, XOR and NOT. These can be useful both for creating complicated conditional statements and processing boolean logic.
Superscalar computers contain multiple ALUs so that they can process several instructions at the same time. Graphics processors and computers with SIMD and MIMD features often provide ALUs that can perform arithmetic on vectors and matrices.
[edit] Memory
Main article: Computer storage
Magnetic core memory was popular main memory for computers through the 1960s until it was completely replaced by semiconductor memory.
A computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered "address" and can store a single number. The computer can be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595". The information stored in memory may represent practically anything. Letters, numbers, even computer instructions can be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is up to the software to give significance to what the memory sees as nothing but a series of numbers.
In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers; either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer can store any kind of information in memory as long as it can be somehow represented in numerical form. Modern computers have billions or even trillions of bytes of memory.
The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. Since data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed.
Computer main memory comes in two principal varieties: random access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM is erased when the power to the computer is turned off while ROM retains its data indefinitely. In a PC, the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the software required to perform the task may be stored in ROM. Software that is stored in ROM is often called firmware because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM by retaining data when turned off but being rewritable like RAM. However, flash memory is typically much slower than conventional ROM and RAM so its use is restricted to applications where high speeds are not required.[14]
In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part.
[edit] Input/output (I/O)
Main article: Input/output
Hard disks are common I/O devices used with computers.
I/O is the means by which a computer receives information from the outside world and sends results back. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include input devices like the keyboard and mouse, and output devices such as the display and printer. Hard disks, floppy disks and optical discs serve as both input and output devices. Computer networking is another form of I/O.
Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O.
[edit] Multitasking
Main article: Computer multitasking
While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by having the computer switch rapidly between running each program in turn. One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.
Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.
Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.
[edit] Multiprocessing
Main article: Multiprocessing
Cray designed many supercomputers that used multiprocessing heavily.
Some computers may divide their work between one or more separate CPUs, creating a multiprocessing configuration. Traditionally, this technique was utilized only in large and powerful computers such as supercomputers, mainframe computers and servers. However, multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers have become widely available and are beginning to see increased usage in lower-end markets as a result.
Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers.[15] They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of a the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.
[edit] Networking and the Internet
Main articles: Computer networking and Internet
Visualization of a portion of the routes on the Internet.
Computers have been used to coordinate information in multiple locations since the 1950s, with the US military's SAGE system the first large-scale example of such a system, which led to a number of special-purpose commercial systems like Sabre.
In the 1970s, computer engineers at research institutions throughout the US began to link their computers together using telecommunications technology. This effort was funded by ARPA (now DARPA), and the computer network that it produced was called the ARPANET. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer. Initially these facilities were available primarily to people working in high-tech environments, but in the 1990s the spread of applications like e-mail and the World Wide Web, combined with the development of cheap, fast networking technologies like Ethernet and ADSL saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of personal computers regularly connect to the Internet to communicate and receive information. "Wireless" networking, often utilizing mobile phone networks, has meant networking is becoming increasingly ubiquitous even in mobile computing environments.
[edit] Further topics
[edit] Hardware
Main article: Computer hardware
The term hardware covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.
History of computing hardware First Generation (Mechanical/Electromechanical) Calculators Antikythera mechanism, Difference Engine, Norden bombsight
Programmable Devices Jacquard loom, Analytical Engine, Harvard Mark I, Z3
Second Generation (Vacuum Tubes) Calculators Atanasoff–Berry Computer, IBM 604, UNIVAC 60, UNIVAC 120
Programmable Devices ENIAC, EDSAC, EDVAC, UNIVAC I, IBM 701, IBM 702, IBM 650, Z22
Third Generation (Discrete transistors and SSI, MSI, LSI Integrated circuits) Mainframes IBM 7090, IBM 7080, System/360, BUNCH
Minicomputer PDP-8, PDP-11, System/32, System/36
Fourth Generation (VLSI integrated circuits) Minicomputer VAX, AS/400
4-bit microcomputer Intel 4004, Intel 4040
8-bit microcomputer Intel 8008, Intel 8080, Motorola 6800, Motorola 6809, MOS Technology 6502, Zilog Z80
16-bit microcomputer 8088, Zilog Z8000, WDC 65816/65802
32-bit microcomputer 80386, Pentium, 68000, ARM architecture
64-bit microcomputer[16] x86-64, PowerPC, MIPS, SPARC
Embedded computer 8048, 8051
Personal computer Desktop computer, Home computer, Laptop computer, Personal digital assistant (PDA), Portable computer, Tablet computer, Wearable computer
Server class computer
Theoretical/experimental Quantum computer
Chemical computer
DNA computing
Optical computer
Spintronics based computer
Other Hardware Topics Peripheral device (Input/output) Input Mouse, Keyboard, Joystick, Image scanner
Output Monitor, Printer
Both Floppy disk drive, Hard disk, Optical disc drive, Teleprinter
Computer busses Short range RS-232, SCSI, PCI, USB
Long range (Computer networking) Ethernet, ATM, FDDI
[edit] Software
Main article: Computer software
Software refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc. When software is stored in hardware that cannot easily be modified (such as BIOS ROM in an IBM PC compatible), it is sometimes called "firmware" to indicate that it falls into an uncertain area somewhere between hardware and software.
Computer software Operating system Unix/BSD UNIX System V, AIX, HP-UX, Solaris (SunOS), FreeBSD, NetBSD, IRIX
GNU/Linux List of Linux distributions, Comparison of Linux distributions
Microsoft Windows Windows 9x, Windows NT, Windows XP, Windows Vista, Windows CE
DOS 86-DOS (QDOS), PC-DOS, MS-DOS, FreeDOS
Mac OS Mac OS classic, Mac OS X
Embedded and real-time List of embedded operating systems
Experimental Amoeba, Oberon/Bluebottle, Plan 9 from Bell Labs
Library Multimedia DirectX, OpenGL, OpenAL
Programming library C standard library, Standard template library
Data Protocol TCP/IP, Kermit, FTP, HTTP, SMTP
File format HTML, XML, JPEG, MPEG, PNG
User interface Graphical user interface (WIMP) Microsoft Windows, GNOME, QNX Photon, CDE, GEM
Text user interface Command line interface, shells
Other
Application Office suite Word processing, Desktop publishing, Presentation program, Database management system, Scheduling & Time management, Spreadsheet, Accounting software
Internet Access Browser, E-mail client, Web server, Mail transfer agent, Instant messaging
Design and manufacturing Computer-aided design, Computer-aided manufacturing, Plant management, Robotic manufacturing, Supply chain management
Graphics Raster graphics editor, Vector graphics editor, 3D modeler, Animation editor, 3D computer graphics, Video editing, Image processing
Audio Digital audio editor, Audio playback, Mixing, Audio synthesis, Computer music
Software Engineering Compiler, Assembler, Interpreter, Debugger, Text Editor, Integrated development environment, Performance analysis, Revision control, Software configuration management
Educational Edutainment, Educational game, Serious game, Flight simulator
Games Strategy, Arcade, Puzzle, Simulation, First-person shooter, Platform, Massively multiplayer, Interactive fiction
Misc Artificial intelligence, Antivirus software, Malware scanner, Installer/Package management systems, File manager
[edit] Programming languages
Programming languages provide various ways of specifying programs for computers to run. Unlike natural languages, programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud. They are generally either translated into machine language by a compiler or an assembler before being run, or translated directly at run time by an interpreter. Sometimes programs are executed by a hybrid method of the two techniques. There are thousands of different programming languages—some intended to be general purpose, others useful only for highly specialized applications.
Programming Languages Lists of programming languages Timeline of programming languages, Categorical list of programming languages, Generational list of programming languages, Alphabetical list of programming languages, Non-English-based programming languages
Commonly used Assembly languages ARM, MIPS, x86
Commonly used High level languages BASIC, C, C++, C#, COBOL, Fortran, Java, Lisp, Pascal
Commonly used Scripting languages JavaScript, Python, Ruby, PHP, Perl, ASP, JSP
[edit] Professions and organizations
As the use of computers has spread throughout society, there are an increasing number of careers involving computers. Following the theme of hardware, software and firmware, the brains of people who work in the industry are sometimes known irreverently as wetware or "meatware".
Computer-related professions Hardware-related Electrical engineering, Electronics engineering, Computer engineering, Telecommunications engineering, Optical engineering, Nanoscale engineering
Software-related Human-computer interaction, Information technology, Software engineering, Scientific computing, Web design, Desktop publishing, Sound recording and reproduction
The need for computers to work well together and to be able to exchange information has spawned the need for many standards organizations, clubs and societies of both a formal and informal nature.
Organizations Standards groups ANSI, IEC, IEEE, IETF, ISO, W3C
Professional Societies ACM, ACM Special Interest Groups, IET, IFIP
Free/Open source software groups Free Software Foundation, Mozilla Foundation, Apache Software Foundation
[edit] See also
Look up Computer in
Wiktionary, the free dictionary.
Wikiquote has a collection of quotations related to:
Computers
Wikimedia Commons has media related to:
Computer
Computability theory
Computer science
Computing
Computers in fiction
Computer security and Computer insecurity
List of computer term etymologies
Virtualization
[edit] Notes
^ merriam-Webster dictionary definition. [1]
^ In 1946, ENIAC consumed an estimated 174 kW. By comparison, a typical personal computer may use around 400 W; over four hundred times less. (Kempf 1961)
^ Early computers such as Atanasoff–Berry, Colossus and ENIAC were able to process between 5 and 100 operations per second. A modern "commodity" microprocessor as of 2007 can process several tens of billion instructions a second internally using a main clock speed of a few billion gigahertz - but instructions are also far more powerful, can process many bits of data at a time, and can run in parallel with other instructions. Top end microprocessors are correspondingly more powerful. For reference, a modern everyday computer may include a multiple core processor, a graphics processor and much other onboard circuitry, each of which operates at speeds of billions of operations a second.
^ The Analytical Engine should not be confused with Babbage's difference engine which was a non-programmable mechanical calculator.
^ This program was designed for the PDP-11 minicomputer and shows some typical things a computer can do. All the text after the semicolons are comments for the benefit of human readers. These have no significance to the computer and are ignored. (Digital Equipment Corporation 1972)
^ Attempts are often made to create programs that can overcome this fundamental limitation of computers. Software that mimics learning and adaptation is part of artificial intelligence.
^ It is not universally true that bugs are solely due to programmer oversight. Computer hardware may fail or may itself have a fundamental problem that produces unexpected results in certain situations. For instance, the Pentium FDIV bug caused some Intel microprocessors in the early 1990s to produce inaccurate results for certain floating point division operations. This was caused by a flaw in the microprocessor design and resulted in a partial recall of the affected devices.
^ Even some later computers were commonly programmed directly in machine code. Some minicomputers like the DEC PDP-8 could be programmed directly from a panel of switches. However, this method was usually used only as part of the booting process. Most modern computers boot entirely automatically by reading a boot program from some non-volatile memory.
^ However, there is sometimes some form of machine language compatibility between different computers. An x86-64 compatible microprocessor like the AMD Athlon 64 is able to run most of the same programs that an Intel Core 2 microprocessor can, as well as programs designed for earlier microprocessors like the Intel Pentiums and Intel 80486. This contrasts with very early commercial computers, which were often one-of-a-kind and totally incompatible with other computers.
^ High level languages are also often interpreted rather than compiled. Interpreted languages are translated into machine code on the fly by another program called an interpreter.
^ Although this is a simple program, it contains a software bug. If the traffic signal is showing red when someone switches the "flash red" switch, it will cycle through green once more before starting to flash red as instructed. This bug is quite easy to fix by changing the program to repeatedly test the switch throughout each "wait" period—but writing large programs that have no bugs is exceedingly difficult.
^ The control unit's rule in interpreting instructions has varied somewhat in the past. While the control unit is solely responsible for instruction interpretation in most modern computers, this is not always the case. Many computers include some instructions that may only be partially interpreted by the control system and partially interpreted by another device. This is especially the case with specialized computing hardware that may be partially self-contained. For example, EDVAC, the first modern stored program computer to be designed, used a central control unit that only interpreted four instructions. All of the arithmetic-related instructions were passed on to its arithmetic unit and further decoded there.
^ Instructions often occupy more than one memory address, so the program counters usually increases by the number of memory locations required to store one instruction.
^ Flash memory also may only be rewritten a limited number of times before wearing out, making it less useful for heavy random access usage. (Verma 1988)
^ However, it is also very common to construct supercomputers out of many pieces of cheap commodity hardware; usually individual computers connected by networks. These so-called computer clusters can often provide supercomputer performance at a much lower cost than customized designs. While custom architectures are still used for most of the most powerful supercomputers, there has been a proliferation of cluster computers in recent years. (TOP500 2006)
^ Most major 64-bit instruction set architectures are extensions of earlier designs. All of the architectures listed in this table existed in 32-bit forms before their 64-bit incarnations were introduced.
Current portable computing systems are cumbersome
Many of us carry three or four digital devices with us, according to Simon Moore of Cambridge University's Computer Laboratory, but soon that figure will be in the hundreds.
"They'll be woven into our clothing as identification markers during manufacture," he said.
"They might tell your washing machine what cycle to use, or monitor bio-signs to alert us to impending illness."
Those predictions came at the launch of the Cambridge-MIT Institute's Pervasive Computing initiative (CMI).
It is part of a transatlantic collaboration between information scientists and engineers at Cambridge University and the Massachusetts Institute of Technology in Boston.
Intelligent agents
As well as ensuring the health of us and our clothes, those ubiquitous digital devices will, by default, be communicators. They will talk to each other and us, wherever we are.
Hot-desking may have been a big trend in the nineties, but future computer users will be truly nomadic, able to access information everywhere.
We have this joke that we want to make computers as pervasive and as unobtrusive as oxygen
Umar Saif, MIT
The challenge for CMI researchers is to build immersive systems that automatically reconfigure data or voice call connections between the full range of digital devices, without getting cut off.
Keeping such systems secure from unauthorised use and attack, will be crucial, as will be the inclusion of intelligent filters that prevent the system pestering us with trivia.
This became patently clear last year when MIT tested a prototype system which monitored a person's location and, seamlessly, used the best available communications device to reach them.
A cell phone call turned into a video-conference call when the researcher entered his office and back to a cell phone call as he left for his car.
But the embryonic system noticed a problem with the researcher's office computer, according to MIT's Umar Saif.
"You couldn't escape from the system", he told Go Digital. "It would find whatever communications that was available and call you.
"The computer was just trying to be helpful, but it turned into the nightmare scenario because there was no way of shutting the system down".
Accessible information
Such pestering from not-so intelligent computer systems in the future will be a real turn-off for users, according to Lancaster University's Professor of Organisational Psychology, Cary Cooper.
"People already suffer from technological overload and it's our fault because we allow the technology to manage us, not the other way around," he said.
Too much information can be overwhelming
"Some of the problems we have are because technologies are created by engineers trying to think of a really interesting tweak.
"Let the e-mail chase the cell phone if someone's away on business and if we can't get him that way, we'll get him some other way.
"But they should think more about the impact of these developments on our lives."
This is what the CMI researchers will be doing, said Dr Saif.
Ultimately, he said, the issue is not about information overload but making the power of computers more accessible to ordinary people with no special skills and with little money to shell out on the kinds of gadgets we rely on today.
Energy efficient processors running on wireless devices with vastly increased battery time will be essential to the CMI's pervasive computing vision, as will enhancements in computer vision and speech processing.
"We have this joke that we want to make computers as pervasive and as unobtrusive as oxygen", he said.
"We want people to use computers without even realising they're using them."
This article is about the machine. For the magazine, see Computer (magazine).
The NASA Columbia Supercomputer.
A computer in a wristwatch.
A computer is a programmable device, usually electronic in nature, that can store, retrieve, and process data.[1] The first programmable electronic computers date to the mid-20th century (around 1940 - 1941), although the concept and various non-electronic and analog models date back before this. Early electronic computers were the size of a large room, and their thermionic valve technology demanded huge amounts of power.[2] Today, computers are based upon tiny integrated circuits, are hundreds of millions to hundreds of billions of times more powerful,[3] and simpler computers can be made small enough to fit into a wrist watch and powered by a simple watch battery.
Personal computers and their portable equivalent, the laptop computer, have come to be an integral part of the modern information age; they are what most people think of as "a computer". However, the most common form of computer in use today is by far the embedded computer. Embedded computers are small, simple devices that are often used to control other devices—for example, they may be found in machines ranging from fighter aircraft to industrial robots, digital cameras, consumer electronics, kitchen and other domestic appliances, hi fi components, cars and other vehicles, medical devices such as hearing aids, mobile phones, and children's toys.
The ability to store and execute programs makes computers extremely versatile and distinguishes them from calculators. The Church–Turing thesis is a mathematical statement of this versatility: Any computer with a certain minimum capability is, in principle, capable of performing the same tasks that any other computer can perform. Therefore, computers with capability and complexity ranging from that of a personal digital assistant to a supercomputer are all able to perform the same computational tasks as long as time and storage capacity are not considerations.
Contents
[hide]
1 History of computing
2 Stored program architecture
2.1 Programs
2.2 Example
3 How computers work
3.1 Control unit
3.2 Arithmetic/logic unit (ALU)
3.3 Memory
3.4 Input/output (I/O)
3.5 Multitasking
3.6 Multiprocessing
3.7 Networking and the Internet
4 Further topics
4.1 Hardware
4.2 Software
4.3 Programming languages
4.4 Professions and organizations
5 See also
6 Notes
7 References
[edit] History of computing
Main article: History of computing
The Jacquard loom was one of the first programmable devices.
It is difficult to define any one device as the earliest computer. The very definition of a computer has changed and it is therefore impossible to identify the first computer. Many devices once called "computers" would no longer qualify as such by today's standards.
Originally, the term "computer" referred to a person who performed numerical calculations (a human computer), often with the aid of a mechanical calculating device. Examples of early mechanical computing devices included the abacus, the slide rule and arguably the astrolabe and the Antikythera mechanism (which dates from about 150-100 BC). The end of the Middle Ages saw a re-invigoration of European mathematics and engineering, and Wilhelm Schickard's 1623 device was the first of a number of mechanical calculators constructed by European engineers.
However, none of those devices fit the modern definition of a computer because they could not be programmed. In 1801, Joseph Marie Jacquard made an improvement to the textile loom that used a series of punched paper cards as a template to allow his loom to weave intricate patterns automatically. The resulting Jacquard loom was an important step in the development of computers because the use of punched cards to define woven patterns can be viewed as an early, albeit limited, form of programmability.
In 1837, Charles Babbage was the first to conceptualize and design a fully programmable mechanical computer that he called "The Analytical Engine".[4] Due to limited finance, and an inability to resist tinkering with the design, Babbage never actually built his Analytical Engine.[2]
Large-scale automated data processing of punched cards was performed for the US Census in 1890 by tabulating machines designed by Herman Hollerith and manufactured by the Computing Tabulating Recording Corporation, which later became IBM. By the end of the 19th century a number of technologies that would later prove useful in the realization of practical computers had begun to appear: the punched card, Boolean algebra, the vacuum tube (thermionic valve) and the teleprinter.
During the first half of the 20th century, many scientific computing needs were met by increasingly sophisticated analog computers, which used a direct mechanical or electrical model of the problem as a basis for computation. However, these were not programmable and generally lacked the versatility and accuracy of modern digital computers.
Defining characteristics of five first operative digital computers Computer Shown working Binary Electronic Programmable Turing complete
Zuse Z3 May 1941 Yes No By punched film stock Yes (1998)
Atanasoff–Berry Computer Summer 1941 Yes Yes No No
Colossus December 1943 / January 1944 Yes Yes Partially, by rewiring No
Harvard Mark I – IBM ASCC 1944 No No By punched paper tape Yes (1998)
ENIAC 1944 No Yes Partially, by rewiring Yes
1948 No Yes By Function Table ROM Yes
A succession of steadily more powerful and flexible computing devices were constructed in the 1930s and 1940s, gradually adding the key features that are seen in modern computers. The use of digital electronics (largely invented by Claude Shannon in 1937) and more flexible programmability were vitally important steps, but defining one point along this road as "the first digital electronic computer" is difficult (Shannon 1940). Notable achievements include:
EDSAC was one of the first computers to implement the stored program (von Neumann) architecture.
Konrad Zuse's electromechanical "Z machines". The Z3 (1941) was the first working machine featuring binary arithmetic, including floating point arithmetic and a measure of programmability. In 1998 the Z3 was proved to be Turing complete, therefore being the world's first operational computer.
The non-programmable Atanasoff–Berry Computer (1941) which used vacuum tube based computation, binary numbers, and regenerative capacitor memory.
The secret British Colossus computer (1944), which had limited programmability but demonstrated that a device using thousands of tubes could be reasonably reliable and electronically reprogrammable. It was used for breaking German wartime codes.
The Harvard Mark I (1944), a large-scale electromechanical computer with limited programmability.
The US Army's Ballistics Research Laboratory ENIAC (1946), which used decimal arithmetic and is sometimes called the first general purpose electronic computer (since Konrad Zuse's Z3 of 1941 used electromagnets instead of electronics). Initially, however, ENIAC had an inflexible architecture which essentially required rewiring to change its programming.
Several developers of ENIAC, recognizing its flaws, came up with a far more flexible and elegant design, which came to be known as the stored program architecture or von Neumann architecture. This design was first formally described by John von Neumann in the paper "First Draft of a Report on the EDVAC", published in 1945. A number of projects to develop computers based on the stored program architecture commenced around this time, the first of these being completed in Great Britain. The first to be demonstrated working was the Manchester Small-Scale Experimental Machine (SSEM) or "Baby". However, the EDSAC, completed a year after SSEM, was perhaps the first practical implementation of the stored program design. Shortly thereafter, the machine originally described by von Neumann's paper—EDVAC—was completed but did not see full-time use for an additional two years.
Nearly all modern computers implement some form of the stored program architecture, making it the single trait by which the word "computer" is now defined. By this standard, many earlier devices would no longer be called computers by today's definition, but are usually referred to as such in their historical context. While the technologies used in computers have changed dramatically since the first electronic, general-purpose computers of the 1940s, most still use the von Neumann architecture. The design made the universal computer a practical reality.
Microprocessors are miniaturized devices that often implement stored program CPUs.
Vacuum tube-based computers were in use throughout the 1950s, but were largely replaced in the 1960s by transistor-based devices, which were smaller, faster, cheaper, used less power and were more reliable. These factors allowed computers to be produced on an unprecedented commercial scale. By the 1970s, the adoption of integrated circuit technology and the subsequent creation of microprocessors such as the Intel 4004 caused another leap in size, speed, cost and reliability. By the 1980s, computers had become sufficiently small and cheap to replace simple mechanical controls in domestic appliances such as washing machines. Around the same time, computers became widely accessible for personal use by individuals in the form of home computers and the now ubiquitous personal computer. In conjunction with the widespread growth of the Internet since the 1990s, personal computers are becoming as common as the television and the telephone and almost all modern electronic devices contain a computer of some kind.
[edit] Stored program architecture
Main articles: Computer program and Computer programming
The defining feature of modern computers which distinguishes them from all other machines is that they can be programmed. That is to say that a list of instructions (the program) can be given to the computer and it will store them and carry them out at some time in the future.
In most cases, computer instructions are simple: add one number to another, move some data from one location to another, send a message to some external device, etc. These instructions are read from the computer's memory and are generally carried out (executed) in the order they were given. However, there are usually specialized instructions to tell the computer to jump ahead or backwards to some other place in the program and to carry on executing from there. These are called "jump" instructions (or branches). Furthermore, jump instructions may be made to happen conditionally so that different sequences of instructions may be used depending on the result of some previous calculation or some external event. Many computers directly support subroutines by providing a type of jump that "remembers" the location it jumped from and another instruction to return to that point.
Program execution might be likened to reading a book. While a person will normally read each word and line in sequence, they may at times jump back to an earlier place in the text or skip sections that are not of interest. Similarly, a computer may sometimes go back and repeat the instructions in some section of the program over and over again until some internal condition is met. This is called the flow of control within the program and it is what allows the computer to perform tasks repeatedly without human intervention.
Comparatively, a person using a pocket calculator can perform a basic arithmetic operation such as adding two numbers with just a few button presses. But to add together all of the numbers from 1 to 1,000 would take thousands of button presses and a lot of time—with a near certainty of making a mistake. On the other hand, a computer may be programmed to do this with just a few simple instructions. For example:
mov #0,sum ; set sum to 0 mov #1,num ; set num to 1 loop: add num,sum ; add num to sum add #1,num ; add 1 to num cmp num,#1000 ; compare num to 1000 ble loop ; if num <= 1000, go back to 'loop' halt ; end of program. stop running Once told to run this program, the computer will perform the repetitive addition task without further human intervention. It will almost never make a mistake and a modern PC can complete the task in about a millionth of a second.[5]
However, computers cannot "think" for themselves in the sense that they only solve problems in exactly the way they are programmed to. An intelligent human faced with the above addition task might soon realize that instead of actually adding up all the numbers one can simply use the equation
and arrive at the correct answer (500,500) with little work.[6] In other words, a computer programmed to add up the numbers one by one as in the example above would do exactly that without regard to efficiency or alternative solutions.
[edit] Programs
A 1970s punched card containing one line from a FORTRAN program. The card reads: "Z(1) = Y + W(1)" and is labelled "PROJ039" for identification purposes.
In practical terms, a computer program might include anywhere from a dozen instructions to many millions of instructions for something like a word processor or a web browser. A typical modern computer can execute billions of instructions every second and nearly never make a mistake over years of operation.
Large computer programs may take teams of computer programmers years to write and the probability of the entire program having been written completely in the manner intended is unlikely. Errors in computer programs are called bugs. Sometimes bugs are benign and do not affect the usefulness of the program, in other cases they might cause the program to completely fail (crash), in yet other cases there may be subtle problems. Sometimes otherwise benign bugs may be used for malicious intent, creating a security exploit. Bugs are usually not the fault of the computer. Since computers merely execute the instructions they are given, bugs are nearly always the result of programmer error or an oversight made in the program's design.[7]
In most computers, individual instructions are stored as machine code with each instruction being given a unique number (its operation code or opcode for short). The command to add two numbers together would have one opcode, the command to multiply them would have a different opcode and so on. The simplest computers are able to perform any of a handful of different instructions, the more complex computers have several hundred to choose from—each with a unique numerical code. Since the computer's memory is able to store numbers, it can also store the instruction codes. This leads to the important fact that entire programs (which are just lists of instructions) can be represented as lists of numbers and can themselves be manipulated inside the computer just as if they were numeric data. The fundamental concept of storing programs in the computer's memory alongside the data they operate on is the crux of the von Neumann, or stored program, architecture. In some cases, a computer might store some or all of its program in memory that is kept separate from the data it operates on. This is called the Harvard architecture after the Harvard Mark I computer. Modern von Neumann computers display some traits of the Harvard architecture in their designs, such as in CPU caches.
While it is possible to write computer programs as long lists of numbers (machine language) and this technique was used with many early computers,[8] it is extremely tedious to do so in practice, especially for complicated programs. Instead, each basic instruction can be given a short name that is indicative of its function and easy to remember—a mnemonic such as ADD, SUB, MULT or JUMP. These mnemonics are collectively known as a computer's assembly language. Converting programs written in assembly language into something the computer can actually understand (machine language) is usually done by a computer program called an assembler. Machine languages and the assembly languages that represent them (collectively termed low-level programming languages) tend to be unique to a particular type of computer. For instance, an ARM architecture computer (such as may be found in a PDA or a hand-held videogame) cannot understand the machine language of an Intel Pentium or the AMD Athlon 64 computer that might be in a PC.[9]
Though considerably easier than in machine language, writing long programs in assembly language is often difficult and error prone. Therefore, most complicated programs are written in more abstract high-level programming languages that are able to express the needs of the computer programmer more conveniently (and thereby help reduce programmer error). High level languages are usually "compiled" into machine language (or sometimes into assembly language and then into machine language) using another computer program called a compiler.[10] Since high level languages are more abstract than assembly language, it is possible to use different compilers to translate the same high level language program into the machine language of many different types of computer. This is part of the means by which software like video games may be made available for different computer architectures such as personal computers and various video game consoles.
The task of developing large software systems is an immense intellectual effort. It has proven, historically, to be very difficult to produce software with an acceptably high reliability, on a predictable schedule and budget. The academic and professional discipline of software engineering concentrates specifically on this problem.
[edit] Example
A traffic light showing red.
Suppose a computer is being employed to drive a traffic light. A simple stored program might say:
Turn off all of the lights
Turn on the red light
Wait for sixty seconds
Turn off the red light
Turn on the green light
Wait for one minute
Turn off the green light
Turn on the yellow light
Wait for two seconds
Turn off the yellow light
Jump to instruction number (2)
With this set of instructions, the computer would cycle the light continually through red, green, yellow and back to red again until told to stop running the program.
However, suppose there is a simple on/off switch connected to the computer that is intended be used to make the light flash red while some maintenance operation is being performed. The program might then instruct the computer to:
Turn off all of the lights
Turn on the red light
Wait for sixty seconds
Turn off the red light
Turn on the green light
Wait for sixty seconds
Turn off the green light
Turn on the yellow light
Wait for two seconds
Turn off the yellow light
If the maintenance switch is NOT turned on then jump to instruction number 2
Turn on the red light
Wait for one second
Turn off the red light
Wait for one second
Jump to instruction number 11
In this manner, the computer is either running the instructions from number (2) to (11) over and over or its running the instructions from (11) down to (16) over and over, depending on the position of the switch.[11]
[edit] How computers work
Main articles: Central processing unit and Microprocessor
A general purpose computer has four main sections: the arithmetic and logic unit (ALU), the control unit, the memory, and the input and output devices (collectively termed I/O). These parts are interconnected by busses, often made of groups of wires.
The control unit, ALU, registers, and basic I/O (and often other hardware closely linked with these) are collectively known as a central processing unit (CPU). Early CPUs were comprised of many separate components but since the mid-1970s CPUs have typically been constructed on a single integrated circuit called a microprocessor.
[edit] Control unit
Main articles: CPU design and Control unit
The control unit (often called a control system or central controller) directs the various components of a computer. It reads and interprets (decodes) instructions in the program one by one. The control system decodes each instruction and turns it into a series of control signals that operate the other parts of the computer.[12] Control systems in advanced computers may change the order of some instructions so as to improve performance.
A key component common to all CPUs is the program counter, a special memory cell (a register) that keeps track of which location in memory the next instruction is to be read from.[13]
Diagram showing how a particular MIPS architecture instruction would be decoded by the control system.
The control system's function is as follows—note that this is a simplified description and some of these steps may be performed concurrently or in a different order depending on the type of CPU:
Read the code for the next instruction from the cell indicated by the program counter.
Decode the numerical code for the instruction into a set of commands or signals for each of the other systems.
Increment the program counter so it points to the next instruction.
Read whatever data the instruction requires from cells in memory (or perhaps from an input device). The location of this required data is typically stored within the instruction code.
Provide the necessary data to an ALU or register.
If the instruction requires an ALU or specialized hardware to complete, instruct the hardware to perform the requested operation.
Write the result from the ALU back to a memory location or to a register or perhaps an output device.
Jump back to step (1).
Since the program counter is (conceptually) just another set of memory cells, it can be changed by calculations done in the ALU. Adding 100 to the program counter would cause the next instruction to be read from a place 100 locations further down the program. Instructions that modify the program counter are often known as "jumps" and allow for loops (instructions that are repeated by the computer) and often conditional instruction execution (both examples of control flow).
It is noticeable that the sequence of operations that the control unit goes through to process an instruction is in itself like a short computer program - and indeed, in some more complex CPU designs, there is another yet smaller computer called a microsequencer that runs a microcode program that causes all of these events to happen.
[edit] Arithmetic/logic unit (ALU)
Main article: Arithmetic logic unit
The ALU is capable of performing two classes of operations: arithmetic and logic.
The set of arithmetic operations that a particular ALU supports may be limited to adding and subtracting or might include multiplying or dividing, trigonometry functions (sine, cosine, etc) and square roots. Some can only operate on whole numbers (integers) whilst others use floating point to represent real numbers—albeit with limited precision. However, any computer that is capable of performing just the simplest operations can be programmed to break down the more complex operations into simple steps that it can perform. Therefore, any computer can be programmed to perform any arithmetic operation—although it will take more time to do so if its ALU does not directly support the operation. An ALU may also compare numbers and return boolean truth values (true or false) depending on whether one is equal to, greater than or less than the other ("is 64 greater than 65?").
Logic operations involve Boolean logic: AND, OR, XOR and NOT. These can be useful both for creating complicated conditional statements and processing boolean logic.
Superscalar computers contain multiple ALUs so that they can process several instructions at the same time. Graphics processors and computers with SIMD and MIMD features often provide ALUs that can perform arithmetic on vectors and matrices.
[edit] Memory
Main article: Computer storage
Magnetic core memory was popular main memory for computers through the 1960s until it was completely replaced by semiconductor memory.
A computer's memory can be viewed as a list of cells into which numbers can be placed or read. Each cell has a numbered "address" and can store a single number. The computer can be instructed to "put the number 123 into the cell numbered 1357" or to "add the number that is in cell 1357 to the number that is in cell 2468 and put the answer into cell 1595". The information stored in memory may represent practically anything. Letters, numbers, even computer instructions can be placed into memory with equal ease. Since the CPU does not differentiate between different types of information, it is up to the software to give significance to what the memory sees as nothing but a series of numbers.
In almost all modern computers, each memory cell is set up to store binary numbers in groups of eight bits (called a byte). Each byte is able to represent 256 different numbers; either from 0 to 255 or -128 to +127. To store larger numbers, several consecutive bytes may be used (typically, two, four or eight). When negative numbers are required, they are usually stored in two's complement notation. Other arrangements are possible, but are usually not seen outside of specialized applications or historical contexts. A computer can store any kind of information in memory as long as it can be somehow represented in numerical form. Modern computers have billions or even trillions of bytes of memory.
The CPU contains a special set of memory cells called registers that can be read and written to much more rapidly than the main memory area. There are typically between two and one hundred registers depending on the type of CPU. Registers are used for the most frequently needed data items to avoid having to access main memory every time data is needed. Since data is constantly being worked on, reducing the need to access main memory (which is often slow compared to the ALU and control units) greatly increases the computer's speed.
Computer main memory comes in two principal varieties: random access memory or RAM and read-only memory or ROM. RAM can be read and written to anytime the CPU commands it, but ROM is pre-loaded with data and software that never changes, so the CPU can only read from it. ROM is typically used to store the computer's initial start-up instructions. In general, the contents of RAM is erased when the power to the computer is turned off while ROM retains its data indefinitely. In a PC, the ROM contains a specialized program called the BIOS that orchestrates loading the computer's operating system from the hard disk drive into RAM whenever the computer is turned on or reset. In embedded computers, which frequently do not have disk drives, all of the software required to perform the task may be stored in ROM. Software that is stored in ROM is often called firmware because it is notionally more like hardware than software. Flash memory blurs the distinction between ROM and RAM by retaining data when turned off but being rewritable like RAM. However, flash memory is typically much slower than conventional ROM and RAM so its use is restricted to applications where high speeds are not required.[14]
In more sophisticated computers there may be one or more RAM cache memories which are slower than registers but faster than main memory. Generally computers with this sort of cache are designed to move frequently needed data into the cache automatically, often without the need for any intervention on the programmer's part.
[edit] Input/output (I/O)
Main article: Input/output
Hard disks are common I/O devices used with computers.
I/O is the means by which a computer receives information from the outside world and sends results back. Devices that provide input or output to the computer are called peripherals. On a typical personal computer, peripherals include input devices like the keyboard and mouse, and output devices such as the display and printer. Hard disks, floppy disks and optical discs serve as both input and output devices. Computer networking is another form of I/O.
Often, I/O devices are complex computers in their own right with their own CPU and memory. A graphics processing unit might contain fifty or more tiny computers that perform the calculations necessary to display 3D graphics. Modern desktop computers contain many smaller computers that assist the main CPU in performing I/O.
[edit] Multitasking
Main article: Computer multitasking
While a computer may be viewed as running one gigantic program stored in its main memory, in some systems it is necessary to give the appearance of running several programs simultaneously. This is achieved by having the computer switch rapidly between running each program in turn. One means by which this is done is with a special signal called an interrupt which can periodically cause the computer to stop executing instructions where it was and do something else instead. By remembering where it was executing prior to the interrupt, the computer can return to that task later. If several programs are running "at the same time", then the interrupt generator might be causing several hundred interrupts per second, causing a program switch each time. Since modern computers typically execute instructions several orders of magnitude faster than human perception, it may appear that many programs are running at the same time even though only one is ever executing in any given instant. This method of multitasking is sometimes termed "time-sharing" since each program is allocated a "slice" of time in turn.
Before the era of cheap computers, the principle use for multitasking was to allow many people to share the same computer.
Seemingly, multitasking would cause a computer that is switching between several programs to run more slowly - in direct proportion to the number of programs it is running. However, most programs spend much of their time waiting for slow input/output devices to complete their tasks. If a program is waiting for the user to click on the mouse or press a key on the keyboard, then it will not take a "time slice" until the event it is waiting for has occurred. This frees up time for other programs to execute so that many programs may be run at the same time without unacceptable speed loss.
[edit] Multiprocessing
Main article: Multiprocessing
Cray designed many supercomputers that used multiprocessing heavily.
Some computers may divide their work between one or more separate CPUs, creating a multiprocessing configuration. Traditionally, this technique was utilized only in large and powerful computers such as supercomputers, mainframe computers and servers. However, multiprocessor and multi-core (multiple CPUs on a single integrated circuit) personal and laptop computers have become widely available and are beginning to see increased usage in lower-end markets as a result.
Supercomputers in particular often have highly unique architectures that differ significantly from the basic stored-program architecture and from general purpose computers.[15] They often feature thousands of CPUs, customized high-speed interconnects, and specialized computing hardware. Such designs tend to be useful only for specialized tasks due to the large scale of program organization required to successfully utilize most of a the available resources at once. Supercomputers usually see usage in large-scale simulation, graphics rendering, and cryptography applications, as well as with other so-called "embarrassingly parallel" tasks.
[edit] Networking and the Internet
Main articles: Computer networking and Internet
Visualization of a portion of the routes on the Internet.
Computers have been used to coordinate information in multiple locations since the 1950s, with the US military's SAGE system the first large-scale example of such a system, which led to a number of special-purpose commercial systems like Sabre.
In the 1970s, computer engineers at research institutions throughout the US began to link their computers together using telecommunications technology. This effort was funded by ARPA (now DARPA), and the computer network that it produced was called the ARPANET. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer. Initially these facilities were available primarily to people working in high-tech environments, but in the 1990s the spread of applications like e-mail and the World Wide Web, combined with the development of cheap, fast networking technologies like Ethernet and ADSL saw computer networking become almost ubiquitous. In fact, the number of computers that are networked is growing phenomenally. A very large proportion of personal computers regularly connect to the Internet to communicate and receive information. "Wireless" networking, often utilizing mobile phone networks, has meant networking is becoming increasingly ubiquitous even in mobile computing environments.
[edit] Further topics
[edit] Hardware
Main article: Computer hardware
The term hardware covers all of those parts of a computer that are tangible objects. Circuits, displays, power supplies, cables, keyboards, printers and mice are all hardware.
History of computing hardware First Generation (Mechanical/Electromechanical) Calculators Antikythera mechanism, Difference Engine, Norden bombsight
Programmable Devices Jacquard loom, Analytical Engine, Harvard Mark I, Z3
Second Generation (Vacuum Tubes) Calculators Atanasoff–Berry Computer, IBM 604, UNIVAC 60, UNIVAC 120
Programmable Devices ENIAC, EDSAC, EDVAC, UNIVAC I, IBM 701, IBM 702, IBM 650, Z22
Third Generation (Discrete transistors and SSI, MSI, LSI Integrated circuits) Mainframes IBM 7090, IBM 7080, System/360, BUNCH
Minicomputer PDP-8, PDP-11, System/32, System/36
Fourth Generation (VLSI integrated circuits) Minicomputer VAX, AS/400
4-bit microcomputer Intel 4004, Intel 4040
8-bit microcomputer Intel 8008, Intel 8080, Motorola 6800, Motorola 6809, MOS Technology 6502, Zilog Z80
16-bit microcomputer 8088, Zilog Z8000, WDC 65816/65802
32-bit microcomputer 80386, Pentium, 68000, ARM architecture
64-bit microcomputer[16] x86-64, PowerPC, MIPS, SPARC
Embedded computer 8048, 8051
Personal computer Desktop computer, Home computer, Laptop computer, Personal digital assistant (PDA), Portable computer, Tablet computer, Wearable computer
Server class computer
Theoretical/experimental Quantum computer
Chemical computer
DNA computing
Optical computer
Spintronics based computer
Other Hardware Topics Peripheral device (Input/output) Input Mouse, Keyboard, Joystick, Image scanner
Output Monitor, Printer
Both Floppy disk drive, Hard disk, Optical disc drive, Teleprinter
Computer busses Short range RS-232, SCSI, PCI, USB
Long range (Computer networking) Ethernet, ATM, FDDI
[edit] Software
Main article: Computer software
Software refers to parts of the computer which do not have a material form, such as programs, data, protocols, etc. When software is stored in hardware that cannot easily be modified (such as BIOS ROM in an IBM PC compatible), it is sometimes called "firmware" to indicate that it falls into an uncertain area somewhere between hardware and software.
Computer software Operating system Unix/BSD UNIX System V, AIX, HP-UX, Solaris (SunOS), FreeBSD, NetBSD, IRIX
GNU/Linux List of Linux distributions, Comparison of Linux distributions
Microsoft Windows Windows 9x, Windows NT, Windows XP, Windows Vista, Windows CE
DOS 86-DOS (QDOS), PC-DOS, MS-DOS, FreeDOS
Mac OS Mac OS classic, Mac OS X
Embedded and real-time List of embedded operating systems
Experimental Amoeba, Oberon/Bluebottle, Plan 9 from Bell Labs
Library Multimedia DirectX, OpenGL, OpenAL
Programming library C standard library, Standard template library
Data Protocol TCP/IP, Kermit, FTP, HTTP, SMTP
File format HTML, XML, JPEG, MPEG, PNG
User interface Graphical user interface (WIMP) Microsoft Windows, GNOME, QNX Photon, CDE, GEM
Text user interface Command line interface, shells
Other
Application Office suite Word processing, Desktop publishing, Presentation program, Database management system, Scheduling & Time management, Spreadsheet, Accounting software
Internet Access Browser, E-mail client, Web server, Mail transfer agent, Instant messaging
Design and manufacturing Computer-aided design, Computer-aided manufacturing, Plant management, Robotic manufacturing, Supply chain management
Graphics Raster graphics editor, Vector graphics editor, 3D modeler, Animation editor, 3D computer graphics, Video editing, Image processing
Audio Digital audio editor, Audio playback, Mixing, Audio synthesis, Computer music
Software Engineering Compiler, Assembler, Interpreter, Debugger, Text Editor, Integrated development environment, Performance analysis, Revision control, Software configuration management
Educational Edutainment, Educational game, Serious game, Flight simulator
Games Strategy, Arcade, Puzzle, Simulation, First-person shooter, Platform, Massively multiplayer, Interactive fiction
Misc Artificial intelligence, Antivirus software, Malware scanner, Installer/Package management systems, File manager
[edit] Programming languages
Programming languages provide various ways of specifying programs for computers to run. Unlike natural languages, programming languages are designed to permit no ambiguity and to be concise. They are purely written languages and are often difficult to read aloud. They are generally either translated into machine language by a compiler or an assembler before being run, or translated directly at run time by an interpreter. Sometimes programs are executed by a hybrid method of the two techniques. There are thousands of different programming languages—some intended to be general purpose, others useful only for highly specialized applications.
Programming Languages Lists of programming languages Timeline of programming languages, Categorical list of programming languages, Generational list of programming languages, Alphabetical list of programming languages, Non-English-based programming languages
Commonly used Assembly languages ARM, MIPS, x86
Commonly used High level languages BASIC, C, C++, C#, COBOL, Fortran, Java, Lisp, Pascal
Commonly used Scripting languages JavaScript, Python, Ruby, PHP, Perl, ASP, JSP
[edit] Professions and organizations
As the use of computers has spread throughout society, there are an increasing number of careers involving computers. Following the theme of hardware, software and firmware, the brains of people who work in the industry are sometimes known irreverently as wetware or "meatware".
Computer-related professions Hardware-related Electrical engineering, Electronics engineering, Computer engineering, Telecommunications engineering, Optical engineering, Nanoscale engineering
Software-related Human-computer interaction, Information technology, Software engineering, Scientific computing, Web design, Desktop publishing, Sound recording and reproduction
The need for computers to work well together and to be able to exchange information has spawned the need for many standards organizations, clubs and societies of both a formal and informal nature.
Organizations Standards groups ANSI, IEC, IEEE, IETF, ISO, W3C
Professional Societies ACM, ACM Special Interest Groups, IET, IFIP
Free/Open source software groups Free Software Foundation, Mozilla Foundation, Apache Software Foundation
[edit] See also
Look up Computer in
Wiktionary, the free dictionary.
Wikiquote has a collection of quotations related to:
Computers
Wikimedia Commons has media related to:
Computer
Computability theory
Computer science
Computing
Computers in fiction
Computer security and Computer insecurity
List of computer term etymologies
Virtualization
[edit] Notes
^ merriam-Webster dictionary definition. [1]
^ In 1946, ENIAC consumed an estimated 174 kW. By comparison, a typical personal computer may use around 400 W; over four hundred times less. (Kempf 1961)
^ Early computers such as Atanasoff–Berry, Colossus and ENIAC were able to process between 5 and 100 operations per second. A modern "commodity" microprocessor as of 2007 can process several tens of billion instructions a second internally using a main clock speed of a few billion gigahertz - but instructions are also far more powerful, can process many bits of data at a time, and can run in parallel with other instructions. Top end microprocessors are correspondingly more powerful. For reference, a modern everyday computer may include a multiple core processor, a graphics processor and much other onboard circuitry, each of which operates at speeds of billions of operations a second.
^ The Analytical Engine should not be confused with Babbage's difference engine which was a non-programmable mechanical calculator.
^ This program was designed for the PDP-11 minicomputer and shows some typical things a computer can do. All the text after the semicolons are comments for the benefit of human readers. These have no significance to the computer and are ignored. (Digital Equipment Corporation 1972)
^ Attempts are often made to create programs that can overcome this fundamental limitation of computers. Software that mimics learning and adaptation is part of artificial intelligence.
^ It is not universally true that bugs are solely due to programmer oversight. Computer hardware may fail or may itself have a fundamental problem that produces unexpected results in certain situations. For instance, the Pentium FDIV bug caused some Intel microprocessors in the early 1990s to produce inaccurate results for certain floating point division operations. This was caused by a flaw in the microprocessor design and resulted in a partial recall of the affected devices.
^ Even some later computers were commonly programmed directly in machine code. Some minicomputers like the DEC PDP-8 could be programmed directly from a panel of switches. However, this method was usually used only as part of the booting process. Most modern computers boot entirely automatically by reading a boot program from some non-volatile memory.
^ However, there is sometimes some form of machine language compatibility between different computers. An x86-64 compatible microprocessor like the AMD Athlon 64 is able to run most of the same programs that an Intel Core 2 microprocessor can, as well as programs designed for earlier microprocessors like the Intel Pentiums and Intel 80486. This contrasts with very early commercial computers, which were often one-of-a-kind and totally incompatible with other computers.
^ High level languages are also often interpreted rather than compiled. Interpreted languages are translated into machine code on the fly by another program called an interpreter.
^ Although this is a simple program, it contains a software bug. If the traffic signal is showing red when someone switches the "flash red" switch, it will cycle through green once more before starting to flash red as instructed. This bug is quite easy to fix by changing the program to repeatedly test the switch throughout each "wait" period—but writing large programs that have no bugs is exceedingly difficult.
^ The control unit's rule in interpreting instructions has varied somewhat in the past. While the control unit is solely responsible for instruction interpretation in most modern computers, this is not always the case. Many computers include some instructions that may only be partially interpreted by the control system and partially interpreted by another device. This is especially the case with specialized computing hardware that may be partially self-contained. For example, EDVAC, the first modern stored program computer to be designed, used a central control unit that only interpreted four instructions. All of the arithmetic-related instructions were passed on to its arithmetic unit and further decoded there.
^ Instructions often occupy more than one memory address, so the program counters usually increases by the number of memory locations required to store one instruction.
^ Flash memory also may only be rewritten a limited number of times before wearing out, making it less useful for heavy random access usage. (Verma 1988)
^ However, it is also very common to construct supercomputers out of many pieces of cheap commodity hardware; usually individual computers connected by networks. These so-called computer clusters can often provide supercomputer performance at a much lower cost than customized designs. While custom architectures are still used for most of the most powerful supercomputers, there has been a proliferation of cluster computers in recent years. (TOP500 2006)
^ Most major 64-bit instruction set architectures are extensions of earlier designs. All of the architectures listed in this table existed in 32-bit forms before their 64-bit incarnations were introduced.
Tuesday, January 22, 2008
Computers Timeline --- From 1936 to 1999
The 20th century was nearly into its fourth decade before the first electronic computer came along, and those early machines were behemoths capable of only the most basic tasks. Today, tiny "handhelds" are used for word processing and storage, delivery of documents and images, inventory management, and remote access by workers to central offices. Programmable electronic devices of all sorts have come to pervade modern society to such a degree that future generations may well designate the 20th century as the Computer Age.
1936 "A Symbolic Analysis of Relay and Switching Circuits"
Electrical engineer and mathematician Claude Shannon, in his master’s thesis, "A Symbolic Analysis of Relay and Switching Circuits," uses Boolean algebra to establish a working model for digital circuits. This paper, as well as later research by Shannon, lays the groundwork for the future telecommunications and computer industries.
1939 First binary digital computers are developed
The first binary digital computers are developed. Bell Labs’s George Stibitz designs the Complex Number Calculator, which performs mathematical operations in binary form using on-off relays, and finds the quotient of two 8-digit numbers in 30 seconds. In Germany, Konrad Zuse develops the first programmable calculator, the Z2, using binary numbers and Boolean algebra—programmed with punched tape.
1939 Atanasoff-Berry Computer, the first electronic computer
John Atanasoff and Clifford Berry at Iowa State College design the first electronic computer. The obscure project, called the Atanasoff-Berry Computer (ABC), incorporates binary arithmetic and electronic switching. Before the computer is perfected, Atanasoff is recruited by the Naval Ordnance Laboratory and never resumes its research and development. However, in the summer of 1941, at Atanasoff’s invitation, computer pioneer John Mauchly of the University of Pennsylvania, visits Atanasoff in Iowa and sees the ABC demonstrated.
1943 First vacuum-tube programmable logic calculator
Colossus, the world’s first vacuum-tube programmable logic calculator, is built in Britain for the purpose of breaking Nazi codes. On average, Colossus deciphers a coded message in two hours.
1945 Specifications of a stored-program computer
Two mathematicians, Briton Alan Turing and Hungarian John von Neumann, work independently on the specifications of a stored-program computer. Von Neumann writes a document describing a computer on which data and programs can be stored. Turing publishes a paper on an Automatic Computing Engine, based on the principles of speed and memory.
1946 First electronic computer put into operation
The first electronic computer put into operation is developed late in World War II by John Mauchly and John Presper Eckert at the University of Pennsylvania’s Moore School of Electrical Engineering. The Electronic Numerical Integrator and Computer (ENIAC), used for ballistics computations, weighs 30 tons and includes 18,000 vacuum tubes, 6,000 switches, and 1,500 relays.
1947 Transistor is invented
John Bardeen, Walter H. Brattain, and William B. Shockley of Bell Telephone Laboratories invent the transistor.
1949 First stored-program compute is built
The Electronic Delay Storage Automatic Calculator (EDSAC), the first stored-program computer, is built and programmed by British mathematical engineer Maurice Wilkes.
1951 First computer designed for U.S. business
Eckert and Mauchly, now with their own company (later sold to Remington Rand), design UNIVAC (UNIVersal Automatic Computer)—the first computer for U.S. business. Its breakthrough feature: magnetic tape storage to replace punched cards. First developed for the Bureau of the Census to aid in census data collection, UNIVAC passes a highly public test by correctly predicting Dwight Eisenhower’s victory over Adlai Stevenson in the 1952 presidential race. But months before UNIVAC is completed, the British firm J. Lyons & Company unveils the first computer for business use, the LEO (Lyons Electronic Office), which eventually calculated the company’s weekly payroll.
1952 First computer compiler
Grace Murray Hopper, a senior mathematician at Eckert-Mauchly Computer Corporation and a programmer for Harvard’s Mark I computer, develops the first computer compiler, a program that translates computer instructions from English into machine language. She later creates Flow-Matic, the first programming language to use English words and the key influence for COBOL (Common Business Oriented Language). Attaining the rank of rear admiral in a navy career that brackets her work at Harvard and Eckert-Mauchly, Hopper eventually becomes the driving force behind many advanced automated programming technologies.
1955 First disk drive for random-access storage of data
IBM engineers led by Reynold Johnson design the first disk drive for random-access storage of data, offering more surface area for magnetization and storage than earlier drums. In later drives a protective "boundary layer" of air between the heads and the disk surface would be provided by the spinning disk itself. The Model 305 Disk Storage unit, later called the Random Access Method of Accounting and Control, is released in 1956 with a stack of fifty 24-inch aluminum disks storing 5 million bytes of data.
1957 FORTRAN becomes commercially available
FORTRAN (for FORmula TRANslation), a high-level programming language developed by an IBM team led by John Backus, becomes commercially available. FORTRAN is a way to express scientific and mathematical computations with a programming language similar to mathematical formulas. Backus and his team claim that the FORTRAN compiler produces machine code as efficient as any produced directly by a human programmer. Other programming languages quickly follow, including ALGOL, intended as a universal computer language, in 1958 and COBOL in 1959. ALGOL has a profound impact on future languages such as Simula (the first object-oriented programming language), Pascal, and C/C++. FORTRAN becomes the standard language for scientific computer applications, and COBOL is developed by the U.S. government to standardize its commercial application programs. Both dominate the computer-language world for the next 2 decades.
1958 Integrated circuit invented
Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor independently invent the integrated circuit. (see Electronics.)
1960 Digital Equipment Corporation introduces the "compact" PDP-1
Digital Equipment Corporation introduces the "compact" PDP-1 for the science and engineering market. Not including software or peripherals, the system costs $125,000, fits in a corner of a room, and doesn’t require air conditioning. Operated by one person, it features a cathode-ray tube display and a light pen. In 1962 at MIT a PDP-1 becomes the first computer to run a video game when Steve Russell programs it to play "Spacewar." The PDP-8, released 5 years later, is the first computer to fully use integrated circuits.
1964 BASIC
Dartmouth professors John Kemeny and Thomas Kurtz develop the BASIC (Beginners All-Purpose Symbolic Instruction Code) programming language specifically for the school's new timesharing computer system. Designed for non-computer-science students, it is easier to use than FORTRAN. Other schools and universities adopt it, and computer manufacturers begin to provide BASIC translators with their systems.
1968 Computer mouse makes its public debut
The computer mouse makes its public debut during a demonstration at a computer conference in San Francisco. Its inventor, Douglas Engelbart of the Stanford Research Institute, also demonstrates other user-friendly technologies such as hypermedia with object linking and addressing. Engelbart receives a patent for the mouse 2 years later.
1970 Palo Alto Research Center (PARC)
Xerox Corporation assembles a team of researchers in information and physical sciences in Palo Alto, California, with the goal of creating "the architecture of information." Over the next 30 years innovations emerging from the Palo Alto Research Center (PARC) include the concept of windows (1972), the first real personal computer (Alto in 1973), laser printers (1973), the concept of WYSIWYG (what you see is what you get) word processors (1974), and EtherNet (1974). In 2002 Xerox PARC incorporates as an independent company—Palo Alto Research Center, Inc.
1975 First home computer is marketed to hobbyists
The Altair 8800, widely considered the first home computer, is marketed to hobbyists by Micro Instrumentation Telemetry Systems. The build-it-yourself kit doesn’t have a keyboard, monitor, or its own programming language; data are input with a series of switches and lights. But it includes an Intel microprocessor and costs less than $400. Seizing an opportunity, fledgling entrepreneurs Bill Gates and Paul Allen propose writing a version of BASIC for the new computer. They start the project by forming a partnership called Microsoft.
1977 Apple II is released
Apple Computer, founded by electronics hobbyists Steve Jobs and Steve Wozniak, releases the Apple II, a desktop personal computer for the mass market that features a keyboard, video monitor, mouse, and random-access memory (RAM) that can be expanded by the user. Independent software manufacturers begin to create applications for it.
1979 First laptop computer is designed
What is thought to be the first laptop computer is designed by William Moggridge of GRiD Systems Corporation in England. The GRiD Compass 1109 has 340 kilobytes of bubble memory and a folding electroluminescent display screen in a magnesium case. Used by NASA in the early 1980s for its shuttle program, the "portable computer" is patented by GriD in 1982.
1979 First commercially successful business application
Harvard MBA student Daniel Bricklin and programmer Bob Frankston launch the VisiCalc spreadsheet for the Apple II, a program that helps drive sales of the personal computer and becomes its first commercially successful business application. VisiCalc owns the spreadsheet market for nearly a decade before being eclipsed by Lotus 1-2-3, a spreadsheet program designed by a former VisiCalc employee.
1981 IBM Personal Computer released
IBM introduces the IBM Personal Computer with an Intel 8088 microprocessor and an operating system—MS-DOS—designed by Microsoft. Fully equipped with 64 kilobytes of memory and a floppy disk drive, it costs under $3,000.
1984 Macintosh is introduced
Apple introduces the Macintosh, a low-cost, plug-and-play personal computer whose central processor fits on a single circuit board. Although it doesn’t offer enough power for business applications, its easy-to-use graphic interface finds fans in education and publishing.
1984 CD-ROM introduced
Phillips and Sony combine efforts to introduce the CD-ROM (compact disc read-only memory), patented in 1970 by James T. Russell. With the advent of the CD, data storage and retrieval shift from magnetic to optical technology. The CD can store more than 300,000 pages worth of information—more than the capacity of 450 floppy disks—meaning it can hold digital text, video, and audio files. Advances in the 1990s allow users not only to read prerecorded CDs but also to download, write, and record information onto their own disks.
1985 Windows 1.0 is released
Microsoft releases Windows 1.0, operating system software that features a Macintosh-like graphical user interface (GUI) with drop-down menus, windows, and mouse support. Because the program runs slowly on available PCs, most users stick to MS-DOS. Higher-powered microprocessors beginning in the late 1980s make the next attempts—Windows 3.0 and Windows 95—more successful.
1991 World Wide Web
The World Wide Web becomes available to the general public.
1992 Personal digital assistant
Apple chairman John Sculley coins the term "personal digital assistant" to refer to handheld computers. One of the first on the market is Apple’s Newton, which has a liquid crystal display operated with a stylus. The more successful Palm Pilot is released by 3Com in 1996.
1999 Palm VII connected organizer
Responding to a more mobile workforce, handheld computer technology leaps forward with the Palm VII connected organizer, the combination of a computer with 2 megabytes of RAM and a port for a wireless phone. At less than $600, the computer weighs 6.7 ounces and operates for up to 3 weeks on two AAA batteries. Later versions offer 8 megabytes of RAM, Internet connectivity, and color screens for less than $500.
Computers Timeline
1 - Binary Computer
2 - EDVAC
3 - UNIVAC
4 - Applications
5 - Personal Computers
Essay - William H. Gates III
1936 "A Symbolic Analysis of Relay and Switching Circuits"
Electrical engineer and mathematician Claude Shannon, in his master’s thesis, "A Symbolic Analysis of Relay and Switching Circuits," uses Boolean algebra to establish a working model for digital circuits. This paper, as well as later research by Shannon, lays the groundwork for the future telecommunications and computer industries.
1939 First binary digital computers are developed
The first binary digital computers are developed. Bell Labs’s George Stibitz designs the Complex Number Calculator, which performs mathematical operations in binary form using on-off relays, and finds the quotient of two 8-digit numbers in 30 seconds. In Germany, Konrad Zuse develops the first programmable calculator, the Z2, using binary numbers and Boolean algebra—programmed with punched tape.
1939 Atanasoff-Berry Computer, the first electronic computer
John Atanasoff and Clifford Berry at Iowa State College design the first electronic computer. The obscure project, called the Atanasoff-Berry Computer (ABC), incorporates binary arithmetic and electronic switching. Before the computer is perfected, Atanasoff is recruited by the Naval Ordnance Laboratory and never resumes its research and development. However, in the summer of 1941, at Atanasoff’s invitation, computer pioneer John Mauchly of the University of Pennsylvania, visits Atanasoff in Iowa and sees the ABC demonstrated.
1943 First vacuum-tube programmable logic calculator
Colossus, the world’s first vacuum-tube programmable logic calculator, is built in Britain for the purpose of breaking Nazi codes. On average, Colossus deciphers a coded message in two hours.
1945 Specifications of a stored-program computer
Two mathematicians, Briton Alan Turing and Hungarian John von Neumann, work independently on the specifications of a stored-program computer. Von Neumann writes a document describing a computer on which data and programs can be stored. Turing publishes a paper on an Automatic Computing Engine, based on the principles of speed and memory.
1946 First electronic computer put into operation
The first electronic computer put into operation is developed late in World War II by John Mauchly and John Presper Eckert at the University of Pennsylvania’s Moore School of Electrical Engineering. The Electronic Numerical Integrator and Computer (ENIAC), used for ballistics computations, weighs 30 tons and includes 18,000 vacuum tubes, 6,000 switches, and 1,500 relays.
1947 Transistor is invented
John Bardeen, Walter H. Brattain, and William B. Shockley of Bell Telephone Laboratories invent the transistor.
1949 First stored-program compute is built
The Electronic Delay Storage Automatic Calculator (EDSAC), the first stored-program computer, is built and programmed by British mathematical engineer Maurice Wilkes.
1951 First computer designed for U.S. business
Eckert and Mauchly, now with their own company (later sold to Remington Rand), design UNIVAC (UNIVersal Automatic Computer)—the first computer for U.S. business. Its breakthrough feature: magnetic tape storage to replace punched cards. First developed for the Bureau of the Census to aid in census data collection, UNIVAC passes a highly public test by correctly predicting Dwight Eisenhower’s victory over Adlai Stevenson in the 1952 presidential race. But months before UNIVAC is completed, the British firm J. Lyons & Company unveils the first computer for business use, the LEO (Lyons Electronic Office), which eventually calculated the company’s weekly payroll.
1952 First computer compiler
Grace Murray Hopper, a senior mathematician at Eckert-Mauchly Computer Corporation and a programmer for Harvard’s Mark I computer, develops the first computer compiler, a program that translates computer instructions from English into machine language. She later creates Flow-Matic, the first programming language to use English words and the key influence for COBOL (Common Business Oriented Language). Attaining the rank of rear admiral in a navy career that brackets her work at Harvard and Eckert-Mauchly, Hopper eventually becomes the driving force behind many advanced automated programming technologies.
1955 First disk drive for random-access storage of data
IBM engineers led by Reynold Johnson design the first disk drive for random-access storage of data, offering more surface area for magnetization and storage than earlier drums. In later drives a protective "boundary layer" of air between the heads and the disk surface would be provided by the spinning disk itself. The Model 305 Disk Storage unit, later called the Random Access Method of Accounting and Control, is released in 1956 with a stack of fifty 24-inch aluminum disks storing 5 million bytes of data.
1957 FORTRAN becomes commercially available
FORTRAN (for FORmula TRANslation), a high-level programming language developed by an IBM team led by John Backus, becomes commercially available. FORTRAN is a way to express scientific and mathematical computations with a programming language similar to mathematical formulas. Backus and his team claim that the FORTRAN compiler produces machine code as efficient as any produced directly by a human programmer. Other programming languages quickly follow, including ALGOL, intended as a universal computer language, in 1958 and COBOL in 1959. ALGOL has a profound impact on future languages such as Simula (the first object-oriented programming language), Pascal, and C/C++. FORTRAN becomes the standard language for scientific computer applications, and COBOL is developed by the U.S. government to standardize its commercial application programs. Both dominate the computer-language world for the next 2 decades.
1958 Integrated circuit invented
Jack Kilby of Texas Instruments and Robert Noyce of Fairchild Semiconductor independently invent the integrated circuit. (see Electronics.)
1960 Digital Equipment Corporation introduces the "compact" PDP-1
Digital Equipment Corporation introduces the "compact" PDP-1 for the science and engineering market. Not including software or peripherals, the system costs $125,000, fits in a corner of a room, and doesn’t require air conditioning. Operated by one person, it features a cathode-ray tube display and a light pen. In 1962 at MIT a PDP-1 becomes the first computer to run a video game when Steve Russell programs it to play "Spacewar." The PDP-8, released 5 years later, is the first computer to fully use integrated circuits.
1964 BASIC
Dartmouth professors John Kemeny and Thomas Kurtz develop the BASIC (Beginners All-Purpose Symbolic Instruction Code) programming language specifically for the school's new timesharing computer system. Designed for non-computer-science students, it is easier to use than FORTRAN. Other schools and universities adopt it, and computer manufacturers begin to provide BASIC translators with their systems.
1968 Computer mouse makes its public debut
The computer mouse makes its public debut during a demonstration at a computer conference in San Francisco. Its inventor, Douglas Engelbart of the Stanford Research Institute, also demonstrates other user-friendly technologies such as hypermedia with object linking and addressing. Engelbart receives a patent for the mouse 2 years later.
1970 Palo Alto Research Center (PARC)
Xerox Corporation assembles a team of researchers in information and physical sciences in Palo Alto, California, with the goal of creating "the architecture of information." Over the next 30 years innovations emerging from the Palo Alto Research Center (PARC) include the concept of windows (1972), the first real personal computer (Alto in 1973), laser printers (1973), the concept of WYSIWYG (what you see is what you get) word processors (1974), and EtherNet (1974). In 2002 Xerox PARC incorporates as an independent company—Palo Alto Research Center, Inc.
1975 First home computer is marketed to hobbyists
The Altair 8800, widely considered the first home computer, is marketed to hobbyists by Micro Instrumentation Telemetry Systems. The build-it-yourself kit doesn’t have a keyboard, monitor, or its own programming language; data are input with a series of switches and lights. But it includes an Intel microprocessor and costs less than $400. Seizing an opportunity, fledgling entrepreneurs Bill Gates and Paul Allen propose writing a version of BASIC for the new computer. They start the project by forming a partnership called Microsoft.
1977 Apple II is released
Apple Computer, founded by electronics hobbyists Steve Jobs and Steve Wozniak, releases the Apple II, a desktop personal computer for the mass market that features a keyboard, video monitor, mouse, and random-access memory (RAM) that can be expanded by the user. Independent software manufacturers begin to create applications for it.
1979 First laptop computer is designed
What is thought to be the first laptop computer is designed by William Moggridge of GRiD Systems Corporation in England. The GRiD Compass 1109 has 340 kilobytes of bubble memory and a folding electroluminescent display screen in a magnesium case. Used by NASA in the early 1980s for its shuttle program, the "portable computer" is patented by GriD in 1982.
1979 First commercially successful business application
Harvard MBA student Daniel Bricklin and programmer Bob Frankston launch the VisiCalc spreadsheet for the Apple II, a program that helps drive sales of the personal computer and becomes its first commercially successful business application. VisiCalc owns the spreadsheet market for nearly a decade before being eclipsed by Lotus 1-2-3, a spreadsheet program designed by a former VisiCalc employee.
1981 IBM Personal Computer released
IBM introduces the IBM Personal Computer with an Intel 8088 microprocessor and an operating system—MS-DOS—designed by Microsoft. Fully equipped with 64 kilobytes of memory and a floppy disk drive, it costs under $3,000.
1984 Macintosh is introduced
Apple introduces the Macintosh, a low-cost, plug-and-play personal computer whose central processor fits on a single circuit board. Although it doesn’t offer enough power for business applications, its easy-to-use graphic interface finds fans in education and publishing.
1984 CD-ROM introduced
Phillips and Sony combine efforts to introduce the CD-ROM (compact disc read-only memory), patented in 1970 by James T. Russell. With the advent of the CD, data storage and retrieval shift from magnetic to optical technology. The CD can store more than 300,000 pages worth of information—more than the capacity of 450 floppy disks—meaning it can hold digital text, video, and audio files. Advances in the 1990s allow users not only to read prerecorded CDs but also to download, write, and record information onto their own disks.
1985 Windows 1.0 is released
Microsoft releases Windows 1.0, operating system software that features a Macintosh-like graphical user interface (GUI) with drop-down menus, windows, and mouse support. Because the program runs slowly on available PCs, most users stick to MS-DOS. Higher-powered microprocessors beginning in the late 1980s make the next attempts—Windows 3.0 and Windows 95—more successful.
1991 World Wide Web
The World Wide Web becomes available to the general public.
1992 Personal digital assistant
Apple chairman John Sculley coins the term "personal digital assistant" to refer to handheld computers. One of the first on the market is Apple’s Newton, which has a liquid crystal display operated with a stylus. The more successful Palm Pilot is released by 3Com in 1996.
1999 Palm VII connected organizer
Responding to a more mobile workforce, handheld computer technology leaps forward with the Palm VII connected organizer, the combination of a computer with 2 megabytes of RAM and a port for a wireless phone. At less than $600, the computer weighs 6.7 ounces and operates for up to 3 weeks on two AAA batteries. Later versions offer 8 megabytes of RAM, Internet connectivity, and color screens for less than $500.
Computers Timeline
1 - Binary Computer
2 - EDVAC
3 - UNIVAC
4 - Applications
5 - Personal Computers
Essay - William H. Gates III
Computer Crime and its Effects on the World
Computer Crime has become a very large issue in our society today; this paper will look at this issue from a sociological perspective. It will analyze the various crimes that make up computer crime and see what changes it has brought about in the world in which we live in. Computer crime first is a very new problem in our society today and it is crimes that are committed from a computer. These include embezzling, breaking into other computers, cyber porn and various other crimes that have a drastic affect on the society and the institutions that each of us hold to keep our global society running. To first understand computer crime one must understand first what crime is. According to Diana Kendall, “crime is a behavior that violates criminal law and is punishable with fines, jail or other sanctions”(Kendall 1999; 161). Yet since computer technology is so new it has really no laws to govern it. A law is formal norms that are enforced, norms being established rules of behavior. Many of the crimes committed on computers often times go unpunished. As stated by David Pitchford in the London journal Focus when writing on pornography on the Internet, “ the only way illegal pornographers can be caught is through chance leads, tip-offs and telephone tracing” (Focus 1995; p10-12). Many of the crimes that are also committed on computers via the Internet are very new also. New subcultures have formed around the Internet for the possibilities it brings. Computer crime despite the many problems it has brought has also brought some needed social controls to the Internet and as stated before some laws have been formed to protect many of the institutions that because of computer crime have become targets for criminals. Body Now that I have briefly explained computer crime, I will go into further depth into explaining computer crime from the different sociological perspective theories. To start with is the integrationist perspective looks at of society as the sum of the interactions of individuals and groups” (Kendall; 17). Many of those that commit computer crimes are hackers or people who hack into computer systems for both fun and for gaining access to information. They have formed their own subcultures and hold many different beliefs about the information that is stored in personal computers. Said best by J. Thomas McEwen in the article Computer Ethics many hackers believe that “computerized data [is] free and should be accessible to anyone (McEwen 1991; 8-11). A subculture is a group a group of people who share a different set of beliefs that differ significantly from the larger society (Kendall; 604). Besides forming subcultures, many hackers have learned their behavior from other hackers. The behavior they learn seems to lend credibility to Edwin Sutherlands Differential Association Theory "which states that individuals are more likely to deviate from societal norms when they frequently associate with persons who are more favorable toward deviance than conformity (Kendall; 165). According to McEwen most “young computer hackers beliefs come from association with other hackers, not family members and teachers (McEwen 1991; 8-11). Besides the fact that many hackers learn, their ways from other hackers many after arrested are formally labeled as a hacker and a deviant, those who violate cultural norms and beliefs (Kendall; 598) The labeling theory suggests that deviants are those have been labeled as such by others (Kendall; 166). In theory than, after the person has been arrested they than assume that label and act accordingly. As written by David Pitchford in the London magazine, Focus, one hacker after being arrested was not deterred, he instead became a more active and in “92 became cyberspaces first megastar Pitchford; pages 10-13).” It was only after his second arrest that he stopped offences. Besides the interactionist, perspective on computer crime is the conflict theory. “The conflict theory states that people in power maintain their advantage by using the law to protect their own interest.” (Kendall; 168). Under the conflict perspective, hackers and other computer criminals are seen as deviant because many hackers break into large companies for the “mindless desire for glory (Pitchford; pages 10-13). ” However besides hackers lack of any real criminal desires they are still seen as deviant because they blatantly while doing their hacking. Since the Internet is a global tool, many of the crimes that are committed extend beyond national borders. For this reason the advent of computer crime have made the global community smaller. What one hacker does on his computer in another country affects you and I. This can be seen with the recent virus “Love bug”, this virus disabled computer systems world wide (Washington Times, 5/18/2000). Yet, because of the quickly advancing computer technology a cultural lag has been created. A cultural lag is a gap between the technical development of a society and its moral and legal institutions. The “Love bug” virus; a set of commands that change computer programming and sometimes destroy files, one example of a virus is a “worm, which is a self replicating program”(Pitchford pages 10-13). The “love bug” virus in the last month crippled global companies by erasing files of any computer it downloaded into. Yet, since the hacker was from the Philippines, which have no law against “computer hacking he may be able to escape any conviction (Washington Times 5/18/2000).” So the hacker who caused damage of 15 billion worldwide could get away with a crime considered a felony in the U.S. Although computer crime and hacking have become a global problem, it does serve a function in society. Under the functionalist perspective, “society seeks equilibrium within the five institutions of the economy, family, education, government and religion (Kendall; 1999, 14).” So as a hacker destroys either government files or the files on your personal computer, the other institutions are affected. Computer crime serves in society as a way for the computer Internet to police itself by creating better systems that stop hackers from breaking into systems. “After a break in city banks cash management system city bank upgraded it so customers accounts were safer ”(Washington Post 1998). New police divisions have also sprung up to keep an eye on the Internet, the FBI and the Chicago police have units that specialize in computer crime (Chicago Tribune; 1998). While computer crime may cause havoc and unrest, it has made the government and those who control it keep everything in balance. The other institutions are effected also but not as drastically as the economy and the government. Families have become more aware of security on their computers and many people are becoming more educated on those previously shadowy figures known as hackers. Conclusion In conclusion, computer crime does have a drastic affect on the world in which we live. It affects every person no matter where they are from. It has made those who committed the crimes into top head lines. It is ironic that those who in secret break into computers across the world for enjoyment have been labeled as deviance. Many hackers view the Internet as public space for everyone and do not see their actions as criminal. Hackers are as old as the Internet and many have been instrumental in making the Internet what it is now. Yet, despite this view popular culture and society have labeled hackers and computer criminals as deviance. In my view point hacking and computer crime will be with us for as long as we have the Internet. It is our role to keep the balance between what is a crime and what is done for pure enjoyment. Luckily, the government is making an effort to control the Internet. Yet, true control over the Internet is impossible, because the reasons the Internet was created. This is why families and the institution of education of is needed, parents need to let their children know what is okay to do on the computer and what is not and to educate them on the repercussions of their actions should they choose to become part of the subculture of hackers. In finishing this paper, the true nature of what computer crime will include in the future is unknown. What was criminal yesterday may not be a crime the next day because advances in computers may not allow it. Passwords might be replaced for more secure forms of security, and hackers could be a dying breed. This seems unlikely until the world starts the work as one to control the Internet and those that abuse its power and seek to take what is not theirs. Yet, as best said by Richard Power spokesman for the Computer Security Institute, “ the technologies are very new and they’re very vulnerable, we in going to be in a messy situation for a while”(Chicago Tribune; 1998).
5 Sure-Fire Tips for Buying a New Computer
So you're thinking of buying a new computer... Where do you start? There are so many brands and models of computers available, and it can all be a little overwhelming when you start to look around. How do you decide what type of computer you need? And perhaps more importantly, how do you decide what the best value is? I have sold computers professionally for almost 20 years, and there are certain "tricks of the trade" that most computer stores and salespeople use. Knowing these secrets can make your decision easier and will help you buy the right computer for your needs. 1. Buy What You Need, Maybe a Little More One of the most important things you can do when buying a new computer is make a list of the things that you will be using it for. There are so many different models - with different capabilities - that you can easily buy more, or less, than you really need if you don't. If this is your first computer, this can be a little tougher. Until you've used a computer, it's hard to know exactly what you might want to do with it beyond the obvious, like connecting to the internet. Regardless, you should think about some of the things you might want to do. Some possibilities include: - Connect to the internet - Play games - Digital photography - Digital video - Type documents - Accounting - Design websites - Programming - Digital scrapbooking - Geneology Some of these things need more power than others. For example, connecting to the internet really doesn't need a lot of power. Even the most basic computer available will probably work just fine. Digital video and many games need a lot more power. If you don't get a fast enough computer with enough memory, you'll be disappointed with the performance. Knowing what you're going to be using your computer for will help your salesperson, whether they're on the phone, the internet or standing in front of you, recommend the best system for your needs. As a general rule you're always better off buying more power than you need rather than less, but buying too much can be a waste of money. 2. Warranty Considerations Computer warranties are one of the most confusing and obscure parts of your purchase. Most manufacturers have cut back on their customer service to the point where poor service has become a given. The three most common options are onsite, carry-in or manufacturer's depot service. Onsite service can be helpful, but think about whether you want to have to be available for a technician to come and diagnose your computer, and possibly have to come back with parts at another time. Carry in service is a good option, but find out whether the service center is factory authorized for warranty repairs, as well as whether the technicians are all certified. Shipping your computer to a factory service center can take a long time - sometimes a number of weeks. It also creates risk that your computer will be damaged or even lost in shipping. In some cases, the manufacturer will even replace your computer with another unit and ship it back to you, rather than repairing it. This can result in your losing any information that was on your system and having to reload all your software. Another aspect of the warranty to find out about is technical support. Find out if the computer manufacturer offers a toll-free phone number and what the quality of service is like. The better computer salespeople will be honest about this and tell you if a company's service leaves something to be desired. You can also do some research on the internet - most of the computer magazines like PC Magazine and PC World have annual customer service comparisons that rate the larger computer companies. Always find out how the warranty is handled before making your decision. Even if it doesn't influence your choice, knowing what to expect if something does go wrong will save some nasty surprises down the road. 3. Can You Negotiate the Price Down? A computer is a relatively large investment - anywhere from a few hundred to a few thousand dollars. Many computer buyers expect that there is a significant amount of "wiggle room" on the price. The reality is that most computer hardware - the physical pieces like the computer, monitor and printer - is sold at very low profit margins. Often, computer systems are even sold at or below the dealer cost. When you're buying a computer, it never hurts to ask for a better deal, but don't be surprised if you only get a few dollars off, if anything. Over the close to 20 years I've sold computers, I watched the profit margins go from over 40% to less than 5%. It's almost embarassing to offer a $20 discount on a $2500 computer system, but that could mean the difference between making and losing money on the sale. What you can do to get the best price is to do some comparison shopping. Most computer stores offer price-matching guarantees, so if you find your computer for less at another store, most dealers will match or beat that price, even if it means they lose money. 4. How Do Computer Stores Make Any Money? You might be wondering how these computer stores make any money if they're selling computer for so little profit. Their money is made on add-on items. The highest profit areas in most computer stores are cables and "consumable" products such as printer ink and paper. Printer ink is a huge money-maker for most computer stores (even more so for the printer manufacturers). Why is this? Once you've bought a printer, you're going to have to replace your ink at some point, and continue to replace it as it runs out. Most chain computer stores and office supply stores that carry a large selection of ink cartridges make more from ink than they do from the computers themselves. Cables also have huge markups. A cable that costs the store $2-3 will often sell for $20-30. That's ten times their cost! If you're buying a new computer, you will likely need to buy some cables. Some items - printers, for example - don't often include the cables needed to hook them up. Many printers also come with "starter" ink cartridges that are only half-full. You might also want to pick up some extra ink cartridges. This is where you should be able to negotiate a better price. Don't expect the salesperson to throw them in for nothing, but they should be willing to offer you a better price. After all, if you're happy with their service, you'll probably continue to buy your ink, paper and other products from that store in the future. 5. What Software is Included? The last secret of buying a new computer has to do with the software that is included. Most new computer systems include quite a few programs and sometimes the value of the software can be quite high. Something to watch out for when looking at the included software is "trial versions" or "limited editions". Many programs that are preloaded are either crippled versions that don't have all the features of the full program, or trial versions that will only run for a certain amount of time before they expire. Computer are often sold with trial versions of the following types of software: - antivirus - firewall - MS Office or other office suites - Accounting - both business and personal The computer manufacturers generally don't make it easy to tell whether the software on their systems are trial versions or limited versions. This is a question that you should specifically ask if you can't find the answer in their promotional information. If you're buying a new computer with trial versions of the software, keep in mind that you will need to pay to continue using it after the trial period is over. This is an added cost that you need to consider as part of your overall budget. These five "secrets" of buying a new computer are fairly common sense, but they are not always made clear up front. Knowing what to ask will help you in two ways. First, you can be sure you are getting the right computer for your needs. Second, if the salesperson or company that you're dealing with explains these things to you without being asked, you'll know you're dealing with someone who is honest and upfront. Knowing you can trust the people you're dealing with is an invaluable feature of your new computer system.
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