Unit 1: Introduction to Computers

What is a Computer?

Let's start with a PowerPoint presentation that will offer a definition of a computer and look at different kinds of computing machines.

A Brief History of Computing

The history of the modern computer started with Charles Babbage, a 19th-century mathematics professor at Cambridge University. Working with Ada Lovelace, he conceived of an Analytical Engine that could be programmed with punched cards to carry out any calculation to 20 digits of accuracy. Virtually every computer in use today follows the basic plan laid out by Babbage. But other events played an important role in the evolution of information processing.

Like the Analytical Engine, the computer is a machine that changes information from one form to another. All computers take in information (input) and give out information (output). The computer’s flexibility isn’t hidden in its hardware. The secret is software, or programs, the instructions that tell the hardware what to do to transform the input data (information in a form that it can read) into the necessary output.

The Information-Processing Machine

Like the Analytical Engine, the computer is a machine that changes information from one form to another. All computers take in information (input) and give out information (output).

The computer's flexibility isn't hidden in hardware, the physical parts of the computer system. The secret is software, or programs, the instructions that tell the hardware what to do to transform the input data into the necessary output. 

The First Real Computers:

In 1939 a young German engineer named Konrad Zuse completed the first programmable, general-purpose digital computer.

In 1939 Iowa State Professor John Atanasoff developed the first electronic digital computer, the AtanasoffBerry Computer (ABC).

In 1944 Harvard professor Howard Aiken completed the Mark I, which used noisy electromechanical relays to calculate five or six times faster than a person could.

John Mauchly teamed up with J. Presper Eckert to help the U.S. effort in World War II by constructing a machine to calculate trajectory tables for new guns. The machine was the ENIAC (Electronic Numerical Integrator and Computer). After the war Mauchly and Eckert started a private company and created UNIVAC 1, the first general-purpose commercial computer.

Evolution and Acceleration:

Computer hardware evolved rapidly, with new technologies replacing old every few years. People sometimes refer to four generations of computers based on the vacuum tube, the transistor, the integrated circuit, and the microprocessor. Each of these new technologies resulted in computer systems that were more reliable, smaller, faster, more efficient, and cheaper. Moore ‘s Law in 1965 predicted that the power of a silicon chip of the same size would double about every 18 months; this prediction has been remarkably accurate ever since.

The Microcomputer Revolution:

A microprocessor contains the critical components of a computer on a silicon chip. Thanks to the microprocessor, the microcomputer revolution began in the mid 1970's with the introduction of low-cost, typewriter-sized computers as powerful as many of the room-sized computers that had come before. Personal computers, or PCs, as microcomputers have come to be known, are now everyday tools in offices, factories, homes, and schools.

All Shapes and Sizes

Mainframes and Supercomputers:

Before the microcomputer revolution, most information processing was done on mainframe computers, room-sized machines with price tags that matched their size. Today large organizations still use mainframes. Travel agents and bank tellers communicate with a mainframe using a computer terminal, a combination keyboard and screen that transfers information to and from the computer. Mainframe computers are capable of communicating with several users simultaneously through a technique called timesharing. Many research scientists and engineers need the computing power of super-fast, super-expensive supercomputers (often called high-performance computers). A timesharing machine can simultaneously serve the needs of many users working on a variety of projects. Smaller multiuser systems called minicomputers used to be common, but these machines have mostly been replaced by workstations, servers, and personal computers.

 

Workstations and PCs:

Servers are computers especially designed to provide software and other resources to other computers over a network. A workstation is a high-end desktop computer with the computing power of a minicomputer at a fraction of the cost. Workstations are widely used by scientists, engineers, Wall Street analysts, animators, and others whose work involves intensive computation. Personal computers are less powerful and less expensive than workstations, but the line between the two categories is growing blurry.

Portable Computers:

Today one of the fastest growing segments of the PC market involves machines that aren’t tied to desktop/portable computers. Portability is a relative term. Flat-screen, battery-powered laptop computers are light enough to rest on your lap while you work or carry like a small briefcase when closed. Today’s typical laptop, commonly called a notebook computer, weighs much less and can be carried like a book inside a briefcase, with room to spare. Subnotebook computers are even smaller. Handheld (palmtop) computers small enough to be tucked into a jacket pocket serve the needs of users who value mobility over a full-sized keyboard and screen.

Embedded Computers and Special-purpose Computers:

Not all computers are general-purpose machines. Many are special-purpose (dedicated) computers that perform specific tasks, ranging from controlling the temperature and humidity in a high-rise office building to monitoring your heart rate while you work out. Embedded computers enhance all kinds of consumer goods: wristwatches, game machines, stereos, videocassette recorders (VCRs), ovens, and even automobiles. Embedded computers are also widely used in industry, the military, and science for controlling a variety of hardware devices, including robots. When a program is immortalized on a silicon chip it becomes firmware, a hybrid of hardware and software.

Computer Connections: The Network Revolution

While the world was still reeling from the impact of the microcomputer revolution, another information technology revolution was quietly building up steam: a network revolution. If current trends continue, we’ll look back on the 1990s as the end of the personal computing era and the beginning of the interpersonal computing era.

The Emergence of Networks:

The first computers were large, expensive, self-contained machines that could process only one job at a time. The invention of timesharing in the 1960s allowed multiple users to connect to a single mainframe computer through individual terminals. When personal computers started replacing terminals, they were often linked together in local area networks so they could share scarce, expensive resources. The advantages of electronic communication and resource sharing were multiplied when smaller networks were joined into wide area networks to span continents and oceans.

The Internet Explosion

A few visionary computer scientists and engineers, with financial backing from the U.S. government, built an experimental network called ARPANET in 1969. This groundbreaking network would become the Internet, the global collection of networks that is radically transforming the way the world uses computers. In its early years the Internet was the domain of researchers, academics, and government officials. In the 1 990s Internet software took giant leaps forward in usability. The biggest changes came with the development of the World Wide Web, a vast tract of the Internet with a multimedia landscape incorporating pictures, sounds, animation, and even video. Today, all kinds of people are signing onto the Internet in record numbers. They use it to communicate with each other, do research, shop, study, browse, and publish their own work. Several companies are developing and marketing low-cost, stripped-down computers designed to function as Internet terminals (or, as they’re sometimes called, Internet computers). Others are developing set-top boxes that allow consumers to connect to the Internet using a TV.

The Internet Culture

Today, all kinds of people are signing onto the Internet in record numbers. They use it to communicate with each other, do research, download music, shop, study, browse, and publish their own work.

Many companies now have intranets - private organizational networks based on Internet technology. Intranets allow people to transmit, share, and store information within an enterprise. Several companies are marketing stripped-down computers designed to function mainly as network terminals, often called network computers or information appliances. These allow people to connect to the Internet without needing a full-blown personal computer.

We can understand computers and information technology by examining them on three levels: explanations, applications, and implications. The concepts underlying computers don’t change quickly; it helps to understand some of those basic concepts.

Applications

Application programs, also known simply as applications, are the software tools that allow a computer to be used for specific purposes:

Word processing and desktop publishing: Word processing is a critical skill for anyone who communicates in writing. It’s by far the application used most by students. 

Desktop publishing uses the personal computer to transform written words into polished, visually exciting publications

Spreadsheets and other number-crunching applications: In business the electronic spreadsheet is the personal computer application that pays the rent, or at least calculates it.

Databases for information storage and retrieval: If word processors and spreadsheets are the most popular PC applications, databases reign supreme in the world of mainframes.

Computer graphics: Computers are able to produce all kinds of graphics, from the charts and graphs produced by spreadsheets to realistic 3-D animation.

Multimedia and hypermedia: Multimedia tools for PCs make it possible to combine audio and video with traditional text and graphics, adding new dimensions to computer communication. Hypermedia tools focus on the interactive capabilities of computers, allowing users to explore a variety of paths through information sources.

Telecommunication and networking: Every day more computers are connected, networked, so they can send information back and forth; we’re entering an era when networking is the norm. Many experts believe that telecommunication, long-distance communication, will be the single most important function of computers in the not-too-distant future.

Artificial intelligence: Artificial intelligence is the branch of computer science that explores using computers in tasks that require intelligence, imagination, and insight, tasks that have traditionally been performed by people rather than machines.

General problem solving: People use computers to solve problems. Programming languages aren’t applications; they are tools that allow you to build and customize applications.

Implications

The potential risks of the computer revolution are:

the threat to personal privacy posed by large databases

the hazards of high-tech crime and the difficulty of keeping data secure

the difficulty of defining and protecting intellectual property

the risks of failure of computer systems

the threat of automation and the dehumanization of work

the abuse of information as a tool of political and economic power

the dangers of dependence on complex technology

The longer-term potential risks of the computer revolution include:

the death of privacy

the blurring of reality

the evolution of intelligence

 

Analytical Engine, application programs (applications), data, embedded computer, firmware, four generations of computers

handheld (palmtop) computer, hardware, high-performance computer, input, integrated circuit, Internet,

laptop computer, mainframe computer, microcomputer, microcomputer revolution, microprocessor, network

network revolution, notebook computer, output, personal computer (PC), personal digital assistant, program

set-top box, silicon chip, software, special-purpose (dedicated) computer, subnotebook computer, supercomputer

terminal, timesharing, workstation, World Wide Web

 Computer Literacy On-Line

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