The Dawn of Digital Revolution

The Origins of Digital Technology

• Charles Babbage attempted to build the "Analytical Engine", a mechanical general-purpose computer, in the 1800s for complex numerical calculations.
• Ada Lovelace collaborated with Babbage and proposed the idea of the computer algorithm (or program) and foresaw that computing machines could be used for more than just number-crunching.

Samuel Morse and the Telegraph

• Samuel Morse, an artist, developed the concept of the single wire telegraph and Morse Code, enabling rapid communication between distant towns.
• Morse Code provided a model for translating information into a simple code that could be transmitted clearly, stored, and processed.
• In Morse Code, messages are translated to and from patterns of dots and dashes, where:
  • The dot is 1 unit in length of time
  • The dash is 3 units
  • The space between letters is 3 units
  • The space between words is 7 units

The Digital Revolution and World War II

• The digital revolution got its start during World War II (1939-1945).

Key Contributors to Digital Technology

• Claude Shannon (1916-2001) is considered the "Father of Information Theory".
  • He invented logic circuits that became the foundation of modern electronic digital computers.
  • He developed ideas for digitizing analog signals to remove noise and secure communication.
• Alan Turing (1912-1954) is considered the "Father of Computer Science and Artificial Intelligence".
  • He developed the concepts of the algorithm and computation with the "Turing Machine", the model for a general-purpose computer.
• John Bardeen, William Shockley, and Walter Brattain discovered the transistor effect in 1947.
  • The transistor is a device made from a sandwich of semiconductors that can be used as a switch or as an amplifier.
  • As a switch, the transistor is the building block of all modern computer processors, memory, and storage.
  • The trio received the Nobel Prize in Physics in 1956.

Digital Signals

• Digital signals represent various types of information, including text, analog signals, sound, and images.
• Analog signals can be converted into digital signals using devices such as sensors and analog-to-digital converters (ADCs).

Representing Text in Digital Form

• Text is composed of characters, which are analog shapes that can be represented digitally.
• Each character is sent as a binary code, which is a series of ones and zeros.
• Binary codes are stored in bytes according to the ASCII table.

Analog Measurements in Digital Form

• Analog measurements, such as weight or temperature, are converted into digital signals using sensors and ADCs.
• Sensors convert the physical quantity into a voltage, which is then converted into a digital signal by the ADC.
• The digital signal is calibrated to the measured quantity and displayed as a decimal value.

Converting Sound into Digital Signals

• Sound is converted into digital signals using a microphone, which converts sound waves into an electrical signal.
• The signal is sampled at regular intervals, such as 44,000 times per second for digital music recordings.
• The sampled voltage is converted into 2-byte data packets using an ADC.

Digital Photos

• Digital images are created by dividing the image into small squares called pixels.
• Each pixel is read as either black or white, depending on the intensity of the light.
• The pixels are then converted into binary numbers, with 0 representing white and 1 representing black.

Color Digital Photos

• Color digital photos use three sensors for each pixel: one red, one green, and one blue.
• The intensity of the red, green, and blue components of the light is converted into a voltage, which is then converted into a binary number.
• The more bits used for the red, green, and blue components, the greater the color depth.

Digital Videos

• Digital videos are made up of a series of digital images taken at regular intervals.
• The number of images taken per second determines the speed of the video, such as 24 images per second for normal speed or 240 images per second for slow motion.

Digital Displays

• Digital displays, such as HDTVs and smartphones, use a regular array of pixels to display images.
• Each pixel contains three color elements, which are set to specific intensities based on the digital representation of the image.
• The digital representation is a string of binary numbers that specify the intensity of each color element in each pixel.

Quality of Representation or Reproduction

• The quality of representation or reproduction depends on the number of measurements (samples) and the number of bits used to represent the measurement.
• More measurements and more bits result in better reproduction, while fewer measurements and fewer bits result in poorer reproduction.

Explore the early beginnings of digital technology, from Charles Babbage's Analytical Engine to Ada Lovelace's pioneering ideas on computer algorithms.