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History of Computing Devices

Jul 4, 2025

Overview

This lecture introduces the history and importance of computing, from ancient calculation tools to mechanical and electro-mechanical machines, setting the stage for modern computers.

The Importance and Role of Computers

  • Computers are fundamental to modern life, managing everything from power grids to manufacturing and communication.
  • Computing has transformed society similarly to the Industrial Revolution by increasing productivity and amplifying human capabilities.

Early Computing Devices

  • The abacus, invented around 2500 BCE, is an early hand-operated calculator for performing arithmetic.
  • Tools like the astrolabe and slide rule assisted with navigation and complex calculations.
  • These devices made calculations faster, easier, and more accurate, broadening access and lowering barriers.

Human Computers and Mechanical Machines

  • The term "computer" originally referred to a person performing calculations, not a machine.
  • Gottfried Leibniz's Step Reckoner (1694) automated addition, subtraction, multiplication, and division using gears.
  • Most people relied on pre-computed tables for complex calculations due to the high cost and slow speed of machines.

Advancements in Automated Calculation

  • Military and scientific needs drove the development of more efficient computation, such as range tables for artillery.
  • Charles Babbage’s Difference Engine was designed to automate polynomial calculations for mathematical tables but was not completed in his lifetime.
  • Babbage conceptualized the Analytical Engine, a general purpose computer with memory and the ability to run sequences of operations.

Foundations of Programming

  • Ada Lovelace wrote theoretical programs for the Analytical Engine, making her the first computer programmer.
  • The Analytical Engine inspired future computer scientists and foreshadowed programmable, automatic machines.

The Rise of Business Machines

  • By the late 1800s, computing devices were mainly used for science and engineering.
  • Census challenges in the U.S. led to Herman Hollerith’s electro-mechanical tabulating machine, which used punch cards to automate data processing.
  • Hollerith’s inventions laid the groundwork for IBM and modern business data processing.

Key Terms & Definitions

  • Abacus — A hand-operated device for performing arithmetic.
  • Human Computer — A person who performs mathematical calculations.
  • Step Reckoner — An early mechanical calculator using gears for arithmetic operations.
  • Difference Engine — Babbage’s mechanical machine for automating polynomial calculations.
  • Analytical Engine — Babbage’s design for a general purpose, programmable computer.
  • Punch Card — Paper card with holes representing data, used for automating computation.

Action Items / Next Steps

  • Review the evolution of computing devices and their impact on society.
  • Prepare for the next lecture on digital computers.