The earliest known tool for use in
computation was the Abacus,
developed in period 2700–2300 BC
The Abacus is a calculating tool
used primarily in parts of Asia for
performing arithmatic processes.
The abacus was in use centuries
before the adoption of the written
modern numeral system.
The word 'computer' comes from the word
compute which means 'to calculate'.
The history of computer development is
often referred to in reference to the different
generations of computing devices.
With each new
generation, speed, power, and computer
memory has proportionately increased.
First Gottfried Leibniz invented his Leibniz
wheels after 1671 while trying to add an
automatic multiplication feature to the Pascaline.
A Leibniz wheel was a cylinder with a set of teeth
of incremental lengths which, when coupled to a
counting wheel, was used in the calculating
engine of a class of mechanical calculators.
The Arithmometer , invented by Thomas de Colmar in 1820 ,was the
first mechanical calculator . This calculator could add and subtract
two numbers directly and could perform long multiplications and
divisions effectively by using a movable accumulator for the result.
In 1822, Charles Babbage invented Difference Engine. A
difference engine is an automatic mechanical calculator designed
to tabulate polynomial functions. Both logarithmic and trigonometric
functions can be approximated by polynomials.
In 1837, Charles Babbage was the first to
conceptualize and design a fully programmable
The Analytical Engine incorporated an arithmetic
logic unit, control flow in the form of conditional
branching and loops, and integrated memory,
making it the first design for a general-purpose
Babbage was never able to complete
construction of any of these machines
due to conflicts with his chief engineer
and inadequate funding.
But , Charles Babbage’s son, Henry Babbage, completed a
simplified version of the analytical engine's computing unit (the mill)
in 1888. He gave a successful demonstration of its use in computing
tables in 1906. The input was provided to the machine via punched
cards and for output, the machine had a curve plotter and a bell.
By the end of the
19th century a
number of ideas
had begun to
tape, and the
During the first
half of the 20th
were met by
these were not
had the ability to
machine not only
In 1936, Alan
with limits on
what can be
thesis claims that
that is possible
performed by an
running on a
In 1937, George
as father of the
invented and built
K” which was the
first to use binary
circuits to perform
The Atanasoff–Berry Computer (ABC) was the world's first
electronic digital computer, not programmable.
In 1946, a model for computer architecture was introduced and became
known as von Neumann Architecture The von Neumann Architecture
introduced an idea of allowing machine instructions and data to share
memory space. The von Neumann model is composed of 3 major parts, the
arithmetic logic unit (ALU), the memory, and the instruction processing unit
Generations of Computer
A generation of computer refers to the
state of improvement in the product
development process. This term is also
used in the different advancements of new
With each new generation, the circuitry has
gotten smaller and more advanced than
the previous generation before it. As a
result of this, speed, power, and computer
memory has proportionately increased.
Each generation of computers is
characterized by major technological
development that fundamentally changed
the way computers operate.
The phrase computing machine gave away,
after the late 1940s, to just Computer. It
receives data from various sources and
combines it with instructions to produce the
A computer consists of 3 parts
Input Device Central Processing Unit
Arithmatic & Logic Unit
In computing, an
input device is any
peripheral (piece of
equipment) used to
provide data and
control signals to a
Central Processing Unit…
A central processing unit (CPU) is the hardware within a
computer that carries out the instructions of a computer
program by performing the basic arithmetical, logical, and
input/output operations of the system.
Two typical components of a CPU are the arithmetic logic
unit (ALU), which performs arithmetic and logical
operations, and the control unit (CU), which extracts
instructions from memory and decodes and executes them,
calling on the ALU when necessary.
A computer can have more than one CPU; this is called
An output device is any
piece of computer
hardware equipment used
to communicate the results
of data processing carried
out by a computer which
converts the electronically
generated information into
Pictorial Representation of Input Devices,
Output Devices & Common Uses…
(A History of Computers)
A Simple Question from…
Sixth Generation Kids….