L1-2

CCIT4085 Information Technology Fundamentals

1.2 - Analog and Digital

• Topics Covered:

  • Difference between Analog and Digital

  • Binary System

  • Conversion between Base-10 and Base-2

  • Encoding of Characters and Colors

Analog and Digital

Differences Between Analog and Digital

• Analog Devices:

  • Recognize data as a continuous measurement of a physical property.

  • Output typically displayed on a meter or graph.

  • Examples include analog clocks, car speedometers, and thermometers.

• Digital Devices:

  • Work with discrete numbers.

  • Describe everything in two states (on/off).

  • Involve short bits of data.

Key Characteristics of Analog and Digital Representations

• Analog Representation:

  • Uses a continuous range of values.

  • Examples: sound waves, height measurements, weight.

• Digital Representation:

  • Uses discrete, finite values.

  • Examples: number of people, ages, integers, prices.

Processing Analog vs. Digital Data

• Analog signals are harder to process (manipulate and modify).

• Digital processing allows for more efficient manipulation after conversion into a digital format.

Data Conversion

Sampling

• Sampling: Capturing the analog data and representing it by a series of numbers.

• The sampling rate must be suitable for accurate representation of the analog signal.

Encoding Methods

• Codec: A device or software that converts analog signals to digital and vice versa.

• Data Types: Generally divided into numeric (numbers) and non-numeric (characters).

Binary System

• Computers primarily use binary (base-2) for representation. Each digit in this system is a bit.

• Bits and Bytes: A byte consists of 8 bits.

Converting Between Systems

• Conversion Base-10 to Base-2: Method to convert decimal numbers to binary. Remainders from divisions give the binary representation.

• Examples of conversions include (118)10 to (1110110)2.

Data Representations

Numeric Data Representation

• Number Systems: Decimal (base-10), binary (base-2), hexadecimal (base-16).

• Different numbers of bits allow representation of varying ranges of values:

  • 8 bits: 256 values

  • 16 bits: 65,536 values

Encoding Non-Numeric Data

• Encoding assigns unique IDs to pieces of data, enabling computers to process non-numeric values.

• ASCII and EBCDIC: Common single-byte encodings used for representing letters, numbers, and special characters.

Multibyte Encoding

• Necessary for more complex languages beyond simple alphabets, e.g., Chinese characters.

• Unicode is a widely recognized encoding that can represent multiple scripts and symbols.

Color Representation

Color Depth

• Refers to the number of bits used to represent colors in digital images.

• Higher color depth allows for a broader range of colors to be displayed, for example:

  • 8-bit Color Depth: 16.7 million colors

  • 10-bit Color Depth: Over 1 billion colors (used in 4K and 8K displays).

Key Takeaways

• Understanding the differences between analog and digital systems is essential for working with technology.

• Digital systems offer advantages in processing, manipulation, and storage efficiency compared to analog systems.

• Proper encoding and conversion techniques are crucial for accuracy in data representation.