Tells you about the History of computers. The various time periods in which the different types of computers were made by decreasing the size of the components used in the computers and increasing the various features in it.

1. By Kawaljeet Kaur

2. What is Computer????
A computer is a device that can receive, process
and store data. They are used as tools in every
part of society together with the Internet.
Computers nowadays are complex.

4. Abacus – approximately 3000 BC
Log Tables – 1614s
Analytical Engines – 1821s
Punch card Devices – 1883s
First Electronic Computers – 1940s
Mainframes – 1950s
Minicomputers – 1960s
Microcomputers – 1970s
Microcomputer Systems – 1980s
Internet – 1990s

5. The history of computers starts out about
2000 years ago, at the birth of the abacus, a
wooden rack holding two horizontal wires with
beads strung on them. When these beads are
moved around, according to
programming rules memorized by the user, all

7. LOG TABLES
• In 1641, John Napier
developed a system
of multiplication and
division using
addition and
subtraction. These
were the famous log
tables.

8. In the early 17 th century, John Napier , a scottish
mathematician, invented another calculating
tool.It used marked strips of wood or bone, side
by side, to multiply and divide. This tool became
known as “Napier’s Bones”.

9. WILLIAM
OUGHTREDBefore we had calculators we had slide rules.The rectangular
slides was invented by William Oughtred. But the invention
of slide rules was made possible by John Napier’s invention of
logarithms .Using this slide rules there were development of
small electronic calculators.

10. BLAISE PASCAL MECHANICAL CALCULATOR
In 17 th century, Blaise pascal a french mathematician, physicist,
Inventor
came up with the mechanical calculator . It was used to perform
simple additions.
And these made a small contribution in the history of computer
also this invention was modified by Gottfried Leibnitz and it
could perform multiplications & divisions.

11. GOTTFRIED LEIBNITZ
In 1673,German inventor perfected the Liebniz Calculator. This
machine sometimes called The Stepped Reckoner. The Liebniz
was also a calculating machine, but much superior to that of the
pascaline. It could do more than add &subtract. But the Liebniz
calculator could also multiply, divide, and find square root of
numbers. A Crank was added to speed up the work of this
calculator .
MATHEMATHICAL CALCULATOR

12. Charles Babbage was an
English polymath. A
mathematician, philosopher,
inventor and mechanical
engineer. Babbage is best
remembered for originating
the concept of a
programmable computer.

13. In 1821,he developed the “Difference Engine” & In
1832, the “Analytical Engine”. Analytical Engine was
considered as a milestone signifying the start of the
computer.
ANALYTICAL ENGINE

14. HERMAN HOLLERITH
Herman Hollerith designed
a punch card system to
calculate the 1880 census,
accomplishing the task in
just three years. He
establishes a company that
would ultimately
become IBM.

16. 1936- Konrad Zuse invented the
Z1 Computer
1942- John Atanasoff and Clifford
Berry created the ABC Computer
1944- John Presper Eckert and
John W. Mauchly came up with
the idea for the ENIAC 1
computer.

18. Z 1 COMPUTERS

19. ABC COMPUTER

20. ENIAC 1 COMPUTER