Early calculating devices

What is a Computer?

The present time is the age of Information Technology. In this era of information there is only one machine – that keeps us up-to date and up to the mark, i.e. a computer. Computer as such can be thought of as an imitating device which imitates mental operations of a person using it.

The role of computers in all spheres of our life cannot be neglected or ignored. For each and every area, let it be newspapers, publishing, satellite communications, weather forecasting, reservation centers, share markets etc., all need continuous inflow and outflow of data and information in large volumes and within very less time. Here, computers come-into picture and takes over to manage large volumes of data at very high speeds. The word “computer” is an English word which means a machine which can compute. Simply speaking computer is a machine which undertakes the work of counting. A computer is an electronic device which converts raw data into meaningful information. In other words, it can be called as a device which takes some input and processes it to give us an output under the control of a set of instructions given in a specified sequence, known as a program. Thus, the definition of a computer can be summed up as —

• an electronic data processing device,
• which processes and rearranges data to give us meaningful and relevant information,
• when given a set of instructions in a sequence.

The development of computer is a gift to human. Computer has made the tedious work a very simple one. Today a computer, not only undertakes the work of calculations but it is also used in space science, engineering, medicine, publishing, forecast of weather etc. However, we must understand that computer is after all a machine which can be considered as a calculating device which work at an enormous speed or it can store, process or retrieve large volumes of data efficiently, but, all this is directly or indirectly dependent on the instructions given to it by its user. It needs to be programmed carefully so as to get outstanding results.

Introduction of Early Calculating Machines

The computer was invented thousands of years ago. Some 3000 years ago i.e. 1000 B.C. Abacus developed a counting machine.

Abacus

Abacus calculating machine was a rectangular frame on which horizontal rods were fixed. These rods had beads. During calculations these beads are pushed back. ABACUS was the first manual calculating device, which was invented by Chinese about 3000 years ago and is still in use. It is a rectangular wooden frame divided into two parts – upper house and lower house. Abacus consists of vertical rods which carry beads in them, used for calculating. Upper house, known as Heaven consists of two beads in each rod and the lower house, known as the Earth contains five beads in each rod. Each bead of heaven is equal to five numbers and each bead of earth is equal to one number. The right most rod denotes the unit’s place and the rods on the left to it represent ten’s hundred’s etc. in succession. When the beads in Heaven part and Earth are not touching the divider, the value of each is zero. When a bead of Heaven part is brought near to the divider, the value of it becomes Five and when the bead of earth part is brought near to the divider, the value of it becomes one.

Napier Bones

Scottish Mathematician, John Napier invented logarithm in 1614 which proved to be very useful in calculations (multiplication and division). Napier used the principle of performing multiplication with the addition on logarithms, he constructed a special device in 1917 which consisted of 10 pieces of cards, (about 9′ inch wide). Each card was divided into 9 squares. Each square was divided diagonally from the bottom left corner to top right corner. Each card was written a multiplication table from 1 to 9 (Tens above the diagonal and units below it). The set of 10 pieces of cards was called as ‘Bones’. More Info..

Slide Rule

This calculating device was invented in 1620 by an English Mathematician William Oughtred which was based on Napier Logarithm. In a Slide Rule, numbers are represented by distances. In this device two movable scales (rulers) are used. One is called Rule and the other is called Slide. The Rule is made up of two set of scales which are joined but there is a space between them which allows free movement of the slide. The slide is also composed of other two sets of scale on both sides. It also has a moving transparent rectangular piece. This rectangular piece is called Cursor. The cursor can more over the Slide Rule freely. On the scales of slide rules, masks are made in such a way that the actual distances from the beginning are proportionate to the logarithms of the number printed on the scale. The distance between two numbers x and y on the Slide Rule will be

log x – log y

The principle for multiplication is sum of the logarithms whereas for division it is the difference of the logarithms. Slide Rule became very popular among Scientists, Engineer, Mathematicians etc. More Info

Pascal Calculator

In 1642 this machine was developed by a French Mathematician Blaise Pascal. At that time, he was only 16 years old. His father was a Tax Superintendent in France and he was always busy in tedious mathematical calculations. Pascal made us his mind to assist his father and reduce his burden. His thought opened the way of invention of this calculator. Pascal’s machine could perform only subtraction and addition. But due to its versatility this machine became very popular. This machine consisted of gears, dials and cogged wheels (wheels having teeth). Each wheel was divided into 10 parts. This wheel was similar to our electric meter wheel. These wheels performed the work of calculations while rotating. This machine had been named after the name of Pascal in his honour. After him, this machine was further developed by a German Mathematician Leibnitz. More Info..
Leibnitz Machine

In 1673 A.D. Gottfrid Leibnitz, a German Mathematician improved Pascal’s Machine and his machine could do addition, substraction, multiplication and division. More Info..

Charles Babbage Machine

Charles Babbage is called the father of modern computers. Charles Babbage was a Professor in Mathematics in Cambridge University, England. He developed his machine called Difference Engine in 1823. This machine could perform algebric expressions and could work on 20 digit numbers. It could calculate the successive values of algebric expressions and helped to prepare tables. After this development, he was inclined to develop another machine “Analytical Engine” so that it could work out mathematical calculations automatically and output could be obtained in the form of printing. Unfortunately his dream could not be fulfilled. At those times components and other devices had not been manufactured. His machine is similar to today’s model. In 1833, Babbage designed Analytical Engine which could do calculations based on given instructions. This was to be the first programmable computer. He was assisted by Lady Ada Lovelace in his work. But the required technology, parts were not available at that time. His Analytical Engine remained a dream. After his death, Lady Ada Lovelace worked on Babbage’s dream and developed Binary Number System. She is called the first programmer. The computer language ADA was named after her, due to her great contribution in this field. More Info..

Punched Cards

The story of invention of punched card is very interesting. Doctor Herman Hollerith was working in Census Department in America. He was working on numerous data and the work was very tedious. At that pace, the work of census was to be completed very late i.e. the census of 1880 was to be completed by 1887. This late census report would have been meaningless. The programme of development of community and other planning was based on census report. Doctor Herman developed a punched card in 1887 which was named Census Machine. This machine produced wonderful results. The census of 1890 was completed in 3 years time. Punched card is an input device which transfers data to the computer. Punched card has a particular size. The characters are punched in the form of codes. Punching machine is used for punching of cards. This machine punches at required places of card. In the process of punching the data/information is stored in the form if codes on the punched card. This data can be easily read by a computer. The data is passed through a Reading Station. The data on the punched card is read by the reader station. The given data is converted into binary codes and can be read very easily by computer. More Info..

Characteristics Of Computers

Computers possess a number of characteristics which have been discussed below :

Speed

The speed of modern computers is amazing. Today, the computers are able to calculate even in pico seconds (10?12 second). A Computer can do more than 3 lac calculations like addition, substraction etc. in only one second. Its internal speed is virtually instantaneous. This characteristic of computers is very important and useful for human because forecasting is easy. Computers can forecast weather in advance and thus the information of the weather can be given well in advance to the people living at sea-shores or in hilly areas.

Accuracy

The accuracy of the computers is consistently very high. The work performed by the computers is error-free and if there is any error, it is due to its wrong use. Mostly the errors are made by the user himself and not by the machine. If the programming is correct and the data feeded into the computer is accurate, then the results§ furnished by the computers are always accurate. Computers are capable of performing almost any job without any sign of tiredness.

Storage

Computer has the capability to store data on a large scale in its memory. A large quantity of data/information can be stored in it and can be recalled in no time in case of need. A computer has two types of memory. One is called permanent and another is temporary. Data or information can be stored temporarily in the Main Memory. This memory is limited. On the other hand the secondary memory is large and the data can be stored permanently. This memory is also termed as Auxiliary Memory. The capacity of memory is measured in terms of bytes. The higher units are Kilobytes, Megabytes and Gigabytes. For storage of data, devices like magnetic tapes, floppies, disks etc. are used.
Versatility

A Computer is capable of performing logical operations. For logical operations it makes use of its internal control (CPU). It can perform the job given to it without any break for a very long duration. It is capable of doing the following functions:

• It transfers the data internally.
• It can perform the functions of comparison.
• It performs arithmetical operation.
• It exchanges information with the outside world.

Due to their characteristics, the computers are being used in designing, science, engineering, hospitals, schools and universities etc.

Automation

Automation is one of the most important characteristics of the computer. Once the command is given to the computer, it can perform the job without the need of human intervention until the completion of the job. If something is to be printed in output form, and the necessary instructions are given to the computer, it transfers the data continuously to the printer until the completion of work. The automation of computers is of utmost importance in Industries.
Diligence

Computer does not suffer from the human traits of tiredness. It is capable of performing the job with full concentration. It can be put to work continuously for several hours and it will perform the job with same speed and accuracy. More Info