Topic One: Introduction To Computer

Computer Training Guide

For Beginners

Microsoft Window XP

Re-Edition

A computer is device that can receive, collect, process and store data. They are used as tools in every part of society together with the Internet. Computers nowadays are complex; there are a lot of different components inside them, and they all serve different purposes. They all need to work together for the computer to work; knowing how a computer works makes it easier to use a computer by being able to understand how a computer will respond.

Computers are machines that perform tasks or calculations according to a set of instructions, or programs. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

Computers work through an interaction of hardware and software. Hardware refers to the parts of a computer that you can see and touch, including the case and everything inside it. The most important piece of hardware is a tiny rectangular chip inside your computer called the central processing unit (CPU), or microprocessor. It's the "brain" of your computer—the part that translates instructions and performs calculations. Hardware items such as your monitor, keyboard, mouse, printer, and other items are often called hardware devices, or devices.

GENERATIONS OF COMPUTERS

The First Generation Computers 1940 – 1954 (Vacuum Tubes)

The first generation of computer makes used Vacuum Tubes. They were very large in size and programming on them was very difficult. Some of the computers of this generation are as follows:-

MARK – I:

This was the first electronic computer developed by Howard Aiken. It was about 15metres long and the wires connecting the various parts of the machine were about 800 Km long. The main advantage of this computer was that it was fully automatic and much more reliable than other electronic computers.

 

ENIAC: 

This was the first fully electronic digital computer developed by J.PRESPER ECKERT and JOHN MAUCHLY.

The full Name of ENIAC is called (Electronic Numerical Integrator and Computer) was the first general-purpose electronic computer. It was built for the United States military to calculate the paths of artillery shells. Physically, ENIAC was enormous, weighing more than 27,000 kilograms (60,000 pounds) and filling a large room. To process data, ENIAC used about 18,000 vacuum tubes, each the size of a small light bulb. The tubes burned out easily and had to be constantly replaced.

EDVAC:        Picture 1.2

EDVAC was also developed by the makers of ENIAC. It was a stored program machine unlike its predecessor. The full name of EDVAC is called (Electronic Discrete Variable Automatic Computer)

The EDVAC was a binary serial computer with automatic addition, subtraction, multiplication, programmed division and automatic checking with an ultrasonic serial memory^[1] capacity of 1,000 44-bit words (later set to 1,024 words, thus giving a memory, in modern terms, of 5.5 kilobytes).

UNIVAC I:              Picture 1.3

UNIVAC was the first commercially available electronic computer developed by J.PRESPER ECKERT and JOHN MAUCHLY. It was also the first computer to handle both numeric and text data. The full name of UNIVAC is called Universal Automatic Computer

Limitation of the First Generation Computer

·        The major limitations of first generation computers were :

·        The operating speed was very low.

·        Power consumption was very high.

·        They required large space for installation.

·        The Programming capability was quite low.

·        Quit larger, they generate lot of heat require special housing.

·        The Medium internal store.

Second Generation Computers 1956-1963 

(Transistor):

The invention of Transistors marked the start of the second generation. These transistors took place of the vacuum tubes used in the first generation computers.

A transistor is a device composed of semi-conductor materials (germanium and silicon) that can both conduct and insulate Transistors switch and modulate electronic current. The transistor was the first device designed to act as both a transmitter, converting sound waves into electronic waves, and resistor, controlling electronic current.

The name transistor comes from the 'trans' of transmitter and 'sistor' of resistor.

First large scale machines were made using these technologies to meet the requirements of atomic energy laboratories. One of the other benefits to the programming group was that the second generation replaced Machine language with the assembly language. Even though complex in itself Assembly language was much easier than the binary code.

These generations are categorized by their technology as follows:

·        ICT(ICL) 1300,

·        BM 1401

Limitations of second-generation computers were:

·        They used transistors as their main component.

·        They were smaller, faster and more efficient than first-generation computers.

·        They also contained all the components we associate with modern-day computers like printer, memory, disk storage, operating system.

·        They are cheaper than the first generation computers.

·        Maintenance requirement is still high.

·        Very costly.

Third Generation Computers 1964-1971 

(Integrate Circuit)

An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small plate ("chip") of semiconductor material, normally silicon. This can be made much smaller than a discrete circuit made from independent components.

Although transistors were great deal of improvement over the vacuum tubes, they generated heat and damaged the sensitive areas of the computer. The Integrate

Circuit(IC) was invented in 1958 by Jack Kirby. It combined electronic components onto a small silicon disc, made from quartz. More advancement made possible the fittings of even more components on a small chip or a semi conductor. Also in third generation computers, the operating systems allowed the machines to run many different applications. These applications were monitored and coordinated by the computer's memory.

·        IBM-360 series,

·        ICL – 1900,

·        ICL – 2903,

·        PDP – 11/45

Limitations of third-generation computers were:

·        They used Integrated Circuits, popularly known as chips.

·        These computers were smaller than the second-generation computers.

·        Capacities of main memory were greatly enlarged.

·        They used an operating system that allowed machines to run many different programs simultaneously.

·        Power requirement became less.

·        Maintenance of IC required sophisticated technology

Fourth Generation 1971-Present (Microprocessors):

The Microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip.

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

As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

Fifth Generation (Present and Beyond) 

Artificial Intelligence:

Fifth generations computers are only in the minds of advance research scientists and being tested out in the laboratories. These computers will be under Artificial Intelligence (AI), they will be able to take commands in an audio visual way and carry out instructions. Many of the operations which require low human intelligence will be performed by these computers.

Parallel Processing is coming and showing the possibility that the power of many CPU's can be used side by side, and computers will be more powerful than those under central processing. Advances in Super Conductor technology will greatly improve the speed of information traffic. Future looks bright for the computers. 

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