History of computers that means in which time period computing machine are developed.
Table of Contents
ABACUS:
- ABACUS was invented by Chinese People in 2500 – 3000 BC.
- This is the first calculating machine made up of wooden frame with beads or balls sliding on wire.
- It consists of bars in horizontal positions on which sets of beads are inserted.

Slide Rule:
- Slide Rule was invented by William Oughtred in 1622.
- First analog device that works on the principle of logarithms.
- It used for Multiplication, Division, Roots, Trigonometry, Logarithm, Exponentiation etc.

Napier’s Bone:
- Napier’s Bone was Developed by English Mathematician John Napier in 1617 AD.
- Used for Multiplication.
- Also used for dividing and taking square root.

Pascal’s Calculator:
- Pascal’s Calculator was developed by Blaise Pascal in 1642.
- It is a Mechanical Calculator capable for addition and subtraction.
- In this machine, numbers were entered by dialing a series of numbered wheels each wheel having numbers from 0 to 9.
- It could perform addition and subtraction up to 8 digits.

Difference Machine:
- Difference Machine was developed by Charles Babbage (called Fathers of computer) in 1821-22.
- It able to perform complex mathematical calculation with 31 digits of precision.
- Used to solve polynomial equations.
Analytical Engine:
- Analytical Engine was developed by Charles Babbage in 1837.
- General programmable machine.
- Able to Addition, subtraction, multiplication and division through the use of stored program.

And here we listed others important inventions:
- Atanasoff Berry Computer (ABC) in 1942: First electronic digital computer
- Hardvard Mark-I in 1944: First automatic electromechanical computer
- ENIAC (Electronic Numerical Integrator and Calculator) in 1946: First general purpose electronic computer.
- EDVAC (Electronic Discrete Variable Automatic Computer) : First Store program computer.
- EDSAC (Electronic Delay Storage Automatic Computer): First practical stored program electronic computer.
- UNIVAC-I (Universal Automatic Computer): First general purpose electronic digital Computer. it is also called the first commercial computer.
Computer Definition, Features, Capabilities & Limitations and Application Are of Computer