History of Computers

Study Notes

Understanding the evolution of computers is crucial for appreciating current technology.
Distinct generations of computers have developed, shaping their capabilities and functionalities.

A computer is defined as a programmable machine that manipulates data via instructions.
Three key characteristics include:
- Response to specific instructions in a defined manner.
- Ability to execute pre-recorded instructions.
- Capability to quickly store and retrieve large data volumes.

“Computers” originally referred to human calculators engaged in mathematical calculations.
First recorded use of the term "computer" dates back to 1613.

Tally Sticks: Early tools for recording numbers and quantities.
Abacus: A mechanical device aiding arithmetic calculations, invented in Babylonia around 2400 B.C. and popularized in China around 500 B.C.

Napier’s Bones: An invention allowing multiplication, division, and root calculations by arranging rods.
Slide Rule: Developed by William Oughtred in 1622, used for multiplication, division, roots, and trigonometry, but not for addition or subtraction.
Pascaline: Created by Blaise Pascal in 1642, it was limited to addition and subtraction and was expensive.
Stepped Reckoner: Invention by Gottfried Wilhelm Leibniz in 1672, capable of automatic addition, subtraction, multiplication, and division.

Jacquard Loom: An automatic loom, invented by Joseph-Marie Jacquard in 1801, controlled by punched cards, marking significant advancements in programming.
Arithmometer: Invented by Thomas De Colmar in 1820, the first reliable mechanical calculator capable of performing basic arithmetic functions and mass production.

Difference Engine & Analytical Engine: Designed by Charles Babbage in 1822 and 1834, respectively. This established foundational principles of mechanical computing.
Ada Lovelace: Recognized as the first computer programmer; she suggested the use of the binary system to Babbage and wrote programs for the Analytical Engine.

Scheutzian Calculation Engine: Invented in 1843, the first printing calculator based on Babbage's designs.
Tabulating Machine: Developed by Herman Hollerith in 1890 for summarizing information and aiding accounting processes.

Harvard Mark I (ASCC): Created by Howard H. Aiken in 1943, recognized as the first electro-mechanical computer.
Z1: The first programmable computer crafted by Konrad Zuse between 1936 to 1938, utilized punch tape for input and output.

Atanasoff-Berry Computer (ABC): The first electronic digital computer, designed by John Atanasoff and Clifford Berry between 1939 and 1942.
ENIAC: First general-purpose electronic computer completed in 1946, developed by Eckert and Mauchly.
EDVAC: The first stored-program computer designed by von Neumann in 1952, capable of holding programs and data in memory.