Describe the early computing machines and their inventors in the dark age.

DEVICES USED IN DARK AGE 

1. Abacus 

About 5,000 years ago 'abacus' was invented in China. It is considered as the first computer. It is a rectangular frame with vertical wires containing a number of beads for representing units, tens, hundreds, thousands and so on. Calculations were done by moving the beads along with the wires. The structure of abacus is divided into two parts, the upper part is called the 'HEAVEN' and lower part the 'EARTH'. 

2. Napier's Rods 

In 1612, John Napier made the first printed use of the decimal point and invented logarithms and he designed a device called Napier's rods or bones. This device consisted of a set of eleven rods or bones with number marked on them. By placing these rods side by side products and quotients of large numbers could be obtained very easily. 

3. Oughtred's Slide rule 

In 1622, Oughtred developed a slide rule based on Napier's logarithms that was uses! by engineers as primary calculator. It was consisted of two movable rulers placed side by side. Each ruler is marked in such a way that the actual distances from the beginning of the ruler are proportional to the logarithm of the numbers printed on the ruler. By sliding the rulers multiplication and division could be done quickly. 

4. Pascaline (Pascal's Calculator) 

In 1640a French mathematician, Blaise Pascal started developing a device to add sums of money. In 1642 he invented the first operating model a numerical wheel calculator. This brass rectangular box,also called a Pascaline, used 8 movable dials to add numbers upto eight figures long. Pascal's device used a base of ten to accomplish this. It could perform addition and subtraction only, while multiplication and divisions were implemented by performing a series of addition and subtractions. In fact this device could really only add, because subtractions were performed using complement techniques. Modern computers use similar complement techniques for subtraction. 

5. G.W. Leibniz's 

Calculator Leibniz improved on Pascal's calculator in 1694 by creating a machine, that could also multiply. Leibniz's mechanical multiplier worked by a system of gears and dials. 

6. Jacquard's Loom 

In ( 820 French Weaver Joseph Marie Jacquard invented the first punch card to control the patterns to be woven. Jacquard's Loom is considered the first significant use of binary automation. 

7. Arithometer 

Charles Xavier Thomas de Colmar, a Frenchman invented a machine in 1820 that could perform the four basic arithmetic operations. Colmar's mechanical calculator, the Arithometer, presented a more practical approach to computing