History of Computers

 

1. Early Mechanical Devices

A. Abacus (circa 3000 BC):

• Considered the first known computing device.

• Used beads on rods to perform basic arithmetic operations.

• Primarily used in ancient China, Mesopotamia, and Egypt.

B. Mechanical Calculators (17th Century):

1. Pascaline (1642):

   • Invented by Blaise Pascal.

   • Performed addition and subtraction using gears and wheels.

2. Leibniz’s Calculator (1694):

   • Developed by Gottfried Wilhelm Leibniz.

   • Extended the Pascaline to include multiplication and division.

C. Analytical Engine (1837):

• Designed by Charles Babbage.

• First concept of a programmable mechanical computer.

• Included components like a mill (processor), store (memory), and punched cards (input/output).

• Often referred to as the precursor to modern computers.

D. Ada Lovelace (1843):

• Worked with Charles Babbage on the Analytical Engine.

• Wrote the first algorithm intended for a machine, making her the first computer programmer.

2. First Generation (1940s-1950s): Vacuum Tubes

• Computers used vacuum tubes for circuitry and magnetic drums for memory.

• Characteristics:

  • Large, slow, expensive, and energy-intensive.

  • Limited programming capabilities, often in machine language or assembly.

Notable Machines:

1. ENIAC (1945):

   • First general-purpose electronic computer.

   • Developed by John Presper Eckert and John Mauchly.

   • Used for military calculations.

2. UNIVAC I (1951):

   • First commercially available computer.

   • Designed for business and administrative purposes.

3. Second Generation (1950s-1960s): Transistors

• Vacuum tubes replaced by transistors, making computers smaller, faster, and more reliable.

• Magnetic cores replaced magnetic drums as primary memory.

• Programming languages like COBOL and FORTRAN emerged.

Notable Machines:

1. IBM 7090:

   • Popular in scientific and engineering applications.

2. DEC PDP-1:

   • A precursor to minicomputers.

4. Third Generation (1960s-1970s): Integrated Circuits (ICs)

• Introduction of ICs combined multiple transistors into a single chip.

• Marked a significant reduction in size and cost while improving performance.

• Users could now interact with computers via keyboards and monitors.

Notable Machines:

1. IBM System/360:

   • First family of computers with backward compatibility.

2. DEC PDP-8:

   • First successful commercial minicomputer.

5. Fourth Generation (1970s-Present): Microprocessors

• Introduction of microprocessors integrated the CPU onto a single chip.

• Personal computers (PCs) became widely available.

• Graphical user interfaces (GUIs) and advanced operating systems like Windows and macOS emerged.

Notable Developments:

1. Intel 4004 (1971):

   • First commercially available microprocessor.

2. Apple II (1977):

   • One of the first successful personal computers.

3. IBM PC (1981):

   • Popularized personal computing.

6. Fifth Generation (Present and Beyond): AI and Emerging Technologies

• Focus on artificial intelligence (AI), machine learning, and quantum computing.

• Parallel processing and cloud computing dominate modern systems.

Notable Innovations:

1. AI Systems:

   • IBM Watson, Google DeepMind.

2. Quantum Computers:

   • Google’s Sycamore, IBM Quantum.

3. IoT Devices:

   • Embedded systems powering smart homes and wearables.