Computer

During World War II, the first computers (electronic machines that perform numerical calculations far faster than humans) were developed by the British and U. S. governments as a result of secret military projects. These first computers did not remain secret for long; they were adopted by private industry, and they quickly grew in usefulness while decreasing in size and cost. Today, computers are ubiquitous household objects, perhaps unrecognized in the form of a tiny microprocessor embedded in a gadget such as a phone or a TV remote. Even defining the word computer may spark a debate, because so many different kinds of computers exist, and they are used for so many different kinds of activities.

The history of computing is complex. The desire for computers had existed for a long time, but technology was net yet advanced enough to realize them. People had hankered after mechanical devices to help with mathematical calculations, inventing the abacus, the slide rule, and a host of mechanical adding machines. But the electronic computer's rapid evolution forever changed science and technology, the military, and the business world, making its invention a milestone for humanity on a par with the invention of the printing press.

The nature of computing

Some people define a computer as a machine for manipulating data according to a list of instructions known as a program. However, this definition may only make sense to people who already know what a computer can do. Computers are extremely versatile. In fact, they are universal information-processing machines, but at the deepest level, what they really do is perform arithmetic. Today, most computers do arithmetic using the binary number system, because a binary number can be represented by an array of on-off switches. Each 0 or 1 digit in the binary number is called a bit. In early electronic computers, the switches used for each digit were electromagnetic switches, also called relays. Later, vacuum tubes replaced electronic relays, and eventually transistors took the place of both relays and tubes. Transisters can now be manufactured as tiny devices, almost molecular in size, embedded within silicon chips. These tiny transistorized computers work on the same principles as the first, giant relay and vacuum tube based computers (which occupied entire buildings).

Computing professions and disciplines

Computers and mathematics are closely related. Initially, mathematicians and scientists were the only users of computers. But today, what we tend to think of as a computer consists not only of the underlying hardware, with its limited instruction set that performs arithmetic, but also an operating system, which is a set of programs which allow people to use the computer more easily. The operating system is software; it allows people to write new programs for the computer. Since the early 1980's, universities started offering degrees in the academic disciplines such as computer science or computer engineering, devoted to the design of hardware and software for computers. These general fields of study soon came to consist of many sub-fields. In addition, most academic disciplines, and most businesses, use computers as tools.

Below are some of the professional and academic disciplines that have evolved to teach the techniques to construct, program, and use computers (terminology varies widely):

• Computer architecture (how to build computer hardware)
• programming languages (specifying how people can write programs)
• compilers (writing the programs that allow people to use a programming language).
• Computer engineering is the branch of electrical engineering that focuses both on hardware and software design, and the interaction between the two.
• Computer science is a traditional name of the academic study of the processes related to computers and computation, such as developing efficient algorithms to perform specific class of tasks. It tackles questions as to whether problems can be solved at all using a computer, how efficiently they can be solved, and how to construct efficient programs to compute solutions. A huge array of specialties has developed within computer science to investigate different classes of problems.
• Software engineering concentrates on methodologies and practices to allow the development of high quality software systems, while minimizing, and reliably estimating, costs and timelines. Software engineers are often called "programmers", because they design and write computer programs.
• Information systems concentrates on the use and deployment of computer systems in a wider organizational (usually business) context. Generally, this manifests itself in the IT department of a larger company.
• Many disciplines have developed at the intersection of computers with other professions; one of many examples is experts in geographical information systems who apply computer technology to problems of managing geographical information.

There are three major professional societies dedicated to computers, the British Computer Society the Association for Computing Machinery and IEEE Computer Society.

See also

• Association for Computing Machinery
• Beowulf cluster
• IEEE Computer Society
• Operating system
• Computer science
• Open source software
• Personal computer
• Internet

Other computers

• Analog computer
• Chemical computer
• DNA computer
• Human computer
• Molecular computer
• Optical computer
• Quantum computer
• Wetware computer

See also Unconventional computing.

Notes and references

http://www97.intel.com/discover/JourneyInside/TJI_Intro_lesson1/default.aspx

External links

• Computer History
• CBC Digital Archives – Computer Invasion: A History of Automation in Canada