History of Computers

The History of Computers

What are Computers?

• Originally, the term "computer" referred to people, predominantly women, who performed repetitive calculations for tasks like creating navigational tables and astronomical almanacs.

Early Computer Operation (People)

• Early computers were human beings doing calculations.

The Need for Mechanization

• Manual computation was prone to boredom, carelessness, and mistakes.
• Inventors sought to mechanize calculations to improve speed and accuracy.

Early Counting Tools

• Early humans used fingers and marks on cave walls for counting.
• Sticks and stones were used to keep track of things.

Abacus

• A counting machine used in China, Greece, and the Middle East.
• Beads were moved along rods to perform addition and subtraction.
• Called "suan pan" in Chinese and "soroban" in Japanese.

Napier’s Bones (John Napier)

• Scottish mathematician, physicist, astronomer, and astrologer (1550-1617).
• Invented Napier’s Bones for multiplication and division.
• The first machine to use the decimal point.

Napier's Bones Example

• Example demonstrates how Napier's Bones are used for multiplication.

Slide Rule (William Oughtred)

• English mathematician (1574-1660).
• Invented the slide rule.
• Introduced the "$\times$ symbol for multiplication and abbreviations "sin" and "cos" for sine and cosine.

Slide Rule Functionality

• Similar to a calculator, capable of adding numbers accurately up to three digits.

Pascaline (Blaise Pascal)

• French mathematician, physicist, inventor, writer, and Catholic philosopher (1623-1662).
• Invented the Pascaline.

Pascal’s Arithmatique

• A calculator using toothed wheels turned by hand.
• Could handle numbers up to 999,999.999.
• Also called the "numerical wheel calculator."
• One of the world's first mechanical adding machines.

Step Reckoner (Gottfried Wilhelm Leibniz)

• German mathematician and philosopher (1646-1716).
• Improved Pascal’s invention.
• Invented the First Calculator called the Step Reckoner

Step Reckoner Details

• Digital mechanical calculator, also known as the Leibniz wheel.
• Could perform addition, subtraction, multiplication, and division.

Jacquard Loom (Joseph Marie Jacquard)

• French silk weaver and inventor (1752-1834).
• Improved on the punched card design of Jacques de Vaucanson's loom.
• Invented the Automatic Loom or the Jacquard Loom

Automatic Loom

• Controlled by punched cards.
• Cards selected threads to create patterns.

Charles Babbage

• English inventor and mathematician (1791-1871).
• Taught math at Cambridge University.
• Invented a viable mechanical computer equivalent to modern digital computers called the difference and analytical engine
• Called the "Father of modern computer"

Babbage's First Computer

• A mechanical device for simple mathematical calculations.
• An automatic, mechanical calculator for tabulating polynomial functions.

Babbage's Second Computer

• Used binary system.
• Used punched cards as input.
• Ada Lovelace (first programmer) was a close friend.
• Intended to combine numerical qualities with letters or other symbols.

Ada Lovelace

• Countess of Lovelace (1815-1852).
• Mathematics prodigy.
• ‘The Enchantress of Numbers’.
• World’s first Programmer

Herman Hollerith

• American statistician (1860–1929).
• Invented a mechanical tabulator using punched cards.
• Founder of one of the companies that later merged into IBM.

Hollerith's Tabulator Use

• Used to count the number of people who lived in the US for more that 50 years.
• Used punched cards as input.

Howard Aiken

• Electrical engineer and physicist (1900 – 1973).
• Conceptual designer behind IBM’s Harvard Mark I Computer.
• Estimated in 1947 that six electronic digital computers would suffice for the entire U.S.

Grace Hopper

• American computer scientist and US Navy Officer.
• One of the first programmers of the Harvard Mark I computer.
• Developed the first compiler for a computer programming language.
• Referred to as "Amazing Grace."
  -Hopper found the first computer