Introduction to Computers

What is a Computer?

• An electronic device that processes data according to instructions.
• Composed of five basic elements: electronic, programmable, storage, retrieval, and processing.
• Accepts data as input, processes it, stores it, and outputs the results.

Data and Information

• Data: Raw, unprocessed facts; the input for computers.
• Information: Processed data; the output of computers.

Four Basic Functions of a Computer

• Input: Feeding data into a computer.
• Process: Manipulating and transforming data into useful information.
• Output: Presenting the processed information.
• Storage: Saving data and outputs for future use.

Capabilities and Limitations of a Computer

• Capabilities:
  • Processes data quickly.
  • Persists in operations.
  • Produces accurate results based on instructions.
  • Stores, recalls, and retrieves information.
  • Verifies accuracy of information.
  • Performs multiple tasks.
• Limitations:
  • Requires human intervention.
  • Has a limited lifespan.
  • Cannot produce information independently.
  • Outputs depend on user inputs.
  • Cannot replace human intelligence.

History of the Computer

Ancient Times

• Abacus: First recorded adding machine, invented in Babylonia around 500 B.C.
• A manual computing device using beads sliding on rods for calculations.

Mechanical Era

• Logarithms: Invented by John Napier in1614. Enabled multiplication and division to be performed with addition and subtraction.
• Pascaline: Mechanical calculator invented by Blaise Pascal in 1642. Performed basic arithmetic operations.
• Stepped Reckoner: Invented by German mathematician Gottfried Leibniz in 1671. Could multiply 5-digit numbers.
• Jacquard Loom: Developed by Joseph-Marie Jacquard in 1822. An automatic weaving machine controlled by punched cards.
• Difference Engine: First modern computer design created by Charles Babbage in 1822. A steam-powered calculating machine for automatically solving mathematical problems.
• Analytical Engine: Also by Charles Babbage. A mechanical machine that took information from punched cards for complex calculations.
• Ada Lovelace: Wrote the first program for Babbage’s Difference Engine. Credited as the first computer programmer. The programming language ADA is named in her honor.

Electromechanical Era

• Punched Card Tabulating Machine: Herman Hollerith used punched cards for census taking in 1890.
• Hollerith's company later became IBM.
• Millionaire: The first efficient four-function calculator invented by Otto Shweiger in 1893.

Electronic Era

• Z3: The first programmable computer built by Konrad Zuse in 1941. It was the first fully functional, program-controlled machine.