This presentation explores the historical development of computers, highlighting the key inventions and milestones that shaped modern computing. It explains each generation of computers with examples, features, and significance — from mechanical devices like the Abacus and Pascaline to today's smart systems. Highlights: Early Computing Devices: Abacus, Napier’s Bones, Slide Rule, etc. Mechanical & Electro-mechanical Computers Generations of Computers (1st to 5th) Key Innovators and Milestones Visual Timeline of Computer Evolution Useful for history of technology lessons, computer science students, and tech enthusiasts.

1. EVOLUTION OF COMPUTERS
JOURNEY OF COMPUTERS: FROM BIG TO POCKET-SIZED
RITIKA SHAR MA

2. WHAT IS COMPUTER EVOLUTION?
The evolution of computers refers to how
computers have changed over time — from
large, slow machines to today's fast, compact
devices like smart phones and tablets.
“Did you know that 400 years ago,
computers were not machines — they
were people?”
 In the old days, humans used to do big
calculations.
 These people were actually called
"computers" — it was their job title!
 Their job was to solve math problems using
paper and brain power.
 Doing these calculations was hard and
expensive, and needed special training.
 The word "computer" was first used in
1613, but it meant a person, not a machine.
Tally Sticks – The First Memory
Tool
A tally stick was a piece of wood
used to count and record numbers
or messages.
People made small cuts or marks
on the stick to track things like:
Money owed
 Number of sheep or goods
 Simple messages

3. ABACUS – THE FIRST
CALCULATOR
 An abacus is an old counting tool used to do math calculations.
 It was made with beads and rods — you move the beads to count.
 The first abacus was used in Babylon (2400 B.C.) and China
(around 500 B.C.).
 It helped people add, subtract, multiply, and divide — just like a
calculator!

4. NAPIER’S BONES – EARLY
CALCULATOR
 It was invented by John Napier in 1614. He was a
Scottish mathematician.
What is it?
Napier’s Bones is a tool that helps people multiply,
divide, and find square and cube roots easily.
It uses rods (sticks) with numbers on them, arranged
in a special way.
 The rods have numbers written in such a way that,
when you place them in a row and follow simple
steps, you can get the answer to complex calculations.
 This tool was very helpful before calculators were
invented.
 People used to move the rods around and place them
in a special wooden or board setup to do calculations
faster.

5. SLIDE RULE
 A slide rule is an early calculating tool.
It was mainly used before electronic calculators
became common.
 Invented by William Oughtred in 1622.
 He used the ideas of another scientist, John
Napier, who discovered logarithms
 The slide rule helped people do:Multiplication
(×),Division (÷),Square Roots
(√),Logarithms,Trigonometry (used in
engineering and science)
 It made hard math easier and faster
It was not used for simple addition or subtraction
 It looked like a ruler with sliding parts.
 People used it by lining up numbers and reading
the results using scales.

6. You had to turn the wheels by hand,
and it would show the result.
What could it do?
The Pascaline could do addition and
subtraction only.
It could not multiply or divide
numbers.
•Very Expensive: The machine was
too costly, so only a few people
could afford it.
•Manual Effort Needed: You had to
operate it by turning wheels, which
needed effort and time.
PASCALINE – THE FIRST
MECHANICAL CALCULATOR
 Inventor:The Pascaline was
invented by Blaise Pascal in
1642.Blaise Pascal was a
French mathematician,
physicist, and inventor.He
made it to help his father, who
worked as a tax officer, to do
calculations faster.
What is the Pascaline?
 Pascaline was a mechanical
machine used for doing math
calculations.
 It worked using gears and
wheels.

7. STEPPED RECKONER – EARLY
MECHANICAL CALCULATOR
Invented by Gottfried Wilhelm Leibniz in 1672. Leibniz was a German
mathematician and philosopher. He improved on Pascal’s calculator by
adding more functions.
It was a mechanical calculator (like a machine).
 It used gears, wheels, and a special mechanism called the “stepped
drum”.
 The machine was operated by turning a crank.
 Unlike Pascaline, this machine could:
 ✅ Add
 ✅ Subtract
 ✅ Multiply
 ✅ Divide
 The Stepped Reckoner was one of the first machines to perform all four
math operations.
 It showed how mechanical machines could automate complex math.

8. DIFFERENCE ENGINE &
ANALYTICAL ENGINE
Difference Engine (1822)
 A mechanical calculator
designed to solve math
problems.
 It was used to make tables of
numbers, like square roots or
logarithms.
 Worked automatically — you
entered the numbers, and it did
the rest.
Invented by: Charles Babbage(also known as the Father of the Computer)
Analytical Engine (1834)
More advanced than the
Difference Engine.
It was the first design of
general-purpose
computer.
It had all the basic parts
of modern computers:
•Input (punched cards)
•Memory (to store data)
•Processor (called the
"mill")
•Output (printed results)

9.  First Computer Programmer – Augusta Ada
Byron
 In 1840, Ada Byron suggested using the binary
system.
 She wrote the first program for Charles
Babbage’s Analytical Engine.
 That’s why she is called the world’s first
computer programmer.

10. SCHEUTZIAN CALCULATION
ENGINE – FIRST PRINTING
CALCULATOR
Invented by Per Georg Scheutz in 1843.
He was a Swedish inventor, lawyer, and engineer.
What is the Scheutzian Engine?
 It is a mechanical calculator.
 It was based on Charles Babbage’s Difference Engine
idea.
 It could do calculations and also print the results
automatically!
What made it special?
 It was the first calculator that could print answers
directly.

11. TABULATING MACHINE – FIRST
DATA PROCESSING MACHINE
 Invented by Herman Hollerith in 1890.
 He was an American statistician and inventor.
What is the Tabulating Machine?
 A mechanical device used to process large amounts of data.
 It read punched cards and counted the data automatically.
 Helped summarize and organize information quickly.
How Did It Work?
 Punched cards were used to enter data.
 The machine had electrical connections that would read the holes
in the cards.
 It would then sort, count, and print the results.

12. HARVARD MARK 1 & Z1
 1. Harvard Mark 1
 What it was: The first big electro-
mechanical computer.
 Who made it: Howard H. Aiken,
along with IBM.
 When: Finished in 1944.
2. Z1
What it was: The first computer
that could be programmed.
Who made it: Konrad Zuse, in
Germany.
When: Built between 1936 and
1938.
How it worked: You told it what to
do using punched paper tapes, and
it gave you results by showing
lights.

13. 1.ENIAC(Electronic
Numerical
Integrator and
Computer)
What it was: A huge
electronic computer
that could do many
different jobs.
Who made it: John
Presper Eckert and
John W. Mauchly.
When: Finished in
1946.
2.UNIVAC(UNIVersal
Automatic Computer
What it was: The first
computer sold for
regular use by
businesses.
Who made it: J. Presper
Eckert and John
Mauchly (the same
people who made
ENIAC!).
ENIAC/UNIVAC/EDVAC
3.EDVAC (Electronic
Discrete Variable
AutomaticCompute)
This computer was
special because it could
keep both instructions
(program) and its
information (data) inside
its own
memory.Designed by
Von Neumann in 1952.

14. OSBORNE 1
 Osborne 1
 What it was: The
first computer you
could actually carry
around!
 When: Released in
1981 by the Osborne
Computer
Corporation.

The First Computer
Company
What it was: The very first
company made just for
computers. It was called
Electronic Controls
Company.
Who started it: J. Presper
Eckert and John Mauchly (the
same people who made ENIAC
and UNIVAC!).
When: Started in 1949.
The First Computer
Company

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