This document summarizes the evolution of early computing devices from the abacus in 2500 BC to the Hollerith tabulating machine in 1890 AD. It describes the abacus, Napier's bones, the slide rule, early mechanical calculators like the Pascaline and Leibniz calculator, the Jacquard loom which used punched cards, Charles Babbage's Analytical Engine, Ada Lovelace's work programming it, and Herman Hollerith's punched card tabulating machine, which laid the foundations for IBM. Key developments included the use of beads to represent digits, rods for multiplication, scales for calculation, and punched cards that could store and process data programmatically.

1. Evolution of Computers

2. a> Abacus (2500 BC)
• Abacus is the first known
calculating machine.
• It contains beads which
represents digits and cords
which represents position
of decimal numbers.
• It could perform addition
subtraction multiplication
and division.
• Even today some complex
calculations that are
performed by advanced
computers are calculated
using abacus.

3. b> Napier’s bones (1614 AD)
• This was invented by John
Napier, a Scottish
mathematician.
• It has 9 bones(rods) each
represent decimal digits 1 to
9. And one fixed rod
representing number 0.
• It was mainly used for
multiplication.

4. C> Slide rule(1633 AD)
• William Oughtred developed the slide rule in the 17th
century ,which has two sets of scales connected together with
a marginal space between them.
• Before the adventure of the electronic calculator, it was the
most commonly used calculation tool in science and
engineering.
• The use of slide rules continued to grow through the 1950s
and 1960s but around 1974 the handheld electronic scientific
calculator were introduced and the use of slide rule decreased.

5. d>Adding Machine -Pascaline(1642AD)
• Pascal's calculator (also known as the arithmetic
machine or Pascaline) is a mechanical calculator invented
by Blaise Pascal in the early 17th century.
• It has 8 movable dials for calculation. Pascal's calculator was
especially successful in the design of its carry mechanism.
• The machine could add, subtract, multiply, and divide.
Multiplication and division were somewhat difficult to do, by
performing multiplication and division by repeated addition and
subtraction

6. e>Leibniz calculator(1650)
• The calculator can add, subtract, multiply, and divide.
• The speed of calculation for multiplication or division
was acceptable. But like the Pascaline, this calculator
required that the operator using the device had to
understand how to turn the wheels and know the way
of performing calculations with the calculator.

7. Jacquard loom(1801)
• In 1801, Joseph Marie Jacquard, a silk-weaver, invented an
improved textile loom.
• The Jacquard loom was the first machine to use punched card.
• These punched cards controlled the weaving, enabling an
ordinary workman to produce the most beautiful patterns .
• Which played a very important role not only in the textile
industry, but also in development of other programmable
machines, such as computers, for example the Analytical
Engine of Charles Babbage.

8. The Difference Engine(1822)
• It was invented by British mathematician Charles
Babbage, he called it a difference engine because it
could evaluate differential equations.
• This analytical engine consisted of five units, which
became the basic principles for the development of
modern computer.

9. • First Programmer((1833)
• Lady Ada Lovelace was an English mathematician and writer,
chiefly known for her work on Charles Babbage's proposed
mechanical general-purpose computer, the Analytical Engine.
• She was the first to recognise that the machine had applications
beyond pure calculation, and created the
first algorithm intended to be carried out by such a machine.
• As a result, she is often regarded as the first to recognise the full
potential of a "computing machine" and the first
computer programmer.

10. Hollerith Tabulating Machine(1890 AD)
• In 1889, an American named Herman
Hollerith invented a counting machine to
count the population of USA.
• This electronic machine used punched cards
for input , output, and storage purpose.
• Hollerith was the founder of the company
IBM(International Business Machines.