The development of computer was posed by the vastness of earlier methods of data processing such as use of fingers and toes, pebbles and grains. These methods were later developed to the use of chalk, pen and other materials, in facilitating human attempt in the field of counting, recording, classification, manipulating, sorting and presentation of information. But still these new methods are tedious and time wasting; also these methods were associated with mistakes, those leads to the new methods of computing till we have the computer of today.
Early Calculating Devices
It is the early counting device invented in china as early as 500 B.C. it consist of beads threaded on a string mounted in a frame. Each row of the beads have different values i.e. units, tenths, hundreds, thousands e.g. and readings are registered on the right hand of the abacus. Abacus is used for addition, subtraction, multiplication and division.
Fig: 1 A Simple Abacus
- Table Of Logarithms
In the year 1617 a Scottish called Nupeir invented a rod called a table of logarithm for easy multiplication and division of large numbers. The table reduces multiplication and division to addition and subtraction
Fig: 2 A Table of Logarithms
- Slide Rule
This is used for rapid mathematical computation invented in the year 1620 by William Oghtred. It is a simple analogue device.
Fig: 3 A Slide Rule
- Mechanical Calculator
It was first invented by Blasé Pascal in the year 1642 when he was at the age of 19 years. This device is used to assist in addition and subtraction of columns on figures. The device has a number of rotating wheels with each gear having 10 teeth. The first gear counted in unit, the second gear in tens and so on.
Fig: 4Mechanical Calculator
- Stepped Reckorner
Godfrey William Von Leibniz (1646-1716) invented more advanced mechanical calculator which not only adds and subtract but also multiply and divides.
Fig: 5 A Stepped Reckorner
- Punch Card Machines
It was first invented by a French textile manufacturer Joseph Jacquard (1752-1884). Then in 1822 Charles Babbage applied the principles of cards into a mathematical operation and called it “Difference Engine”. It is used in calculating and printing of mathematical tables. The steam driven machine was later invented in the year 1833, modified to contain computer components such as memory, Arithmetic Logic Unit (ALU), input device and so on, with the instruction coded and punched unto card. With this modification, the “Difference Engine” was changed to “Analytical Engine”; Babbage was regarded as the father of the computer.
Fig: 6 APunch Card Machine
- Analytical Engine
The first programmer Lady Augusta Ada, the wife of Lovelace a friend to Babbage has documented the work of Babbage, and in her observation of analytical engine, she bring up supporting material in from of program. In addition a Swedish George Sheucts in conjunction with his son Edwards completed the work of Babbage in 1853 and the machine was used to compute expectancy table by British government and the machine won the first computer prize.
Fig: 7 An Analytical Engine.