Intro to cables

Introduction to Cable Types and Data Transfer

  • Focus on cables used for various components in computers

  • Discussion on specifications such as:

    • Data transfer rates

    • Power provision

Understanding Data Measurement

  • Bit: Binary digit representing one of two values (1 or 0)

    • Nibble: 4 bits combined

    • Byte: 8 bits combined

  • Measurement of data storage and transfer represented in:

    • Bits (lowercase b)

    • Bytes (uppercase B)

Example of Data Transfer Rate

  • File of 50 bits takes 2 seconds to transfer:

    • Data transfer rate = 50 bits / 2 seconds = 25 bps (bits per second)

  • Currently, speeds are commonly measured in kilobits, megabits, etc.

Conversion of Bits and Bytes

  • 1,000 bits = 1 kilobit (1 kb)

  • 1 kilobit per second = 1 kbps

  • 1,000 bits = 125 bytes (1 B)

  • 1,000,000 bits = 1 megabit (1 Mb)

  • 1 megabit = 1,000 kilobits

  • 1,000,000 bytes = 1 megabyte (1 MB)

Higher Orders of Measurement

  • 1,000,000,000 bits = 1 gigabit (1 Gb)

  • 1 gigabit = 1,000 megabits

  • 1,000,000,000 bytes = 1 gigabyte (1 GB)

  • 1 trillion bits = 1 terabit (1 Tb)

  • 1 trillion bytes = 1 terabyte (1 TB)

Importance of Notation

  • Lowercase 'b' indicates bits, while uppercase 'B' indicates bytes.

  • Marketing may mislead consumers by using bits instead of bytes.

    • Example:

      • 1 gigabit per second (1 Gb) vs 250 gigabytes per second (250 GB)

      • 1 Gb = 1,000 Mb vs 250 GB = 2,000 Gb

      • 250 GB is actually 8 times bigger than 1 Gb

CompTIA Exam Objective

  • Focus on Objective 3.1: Explain basic cable types, connectors, features, and purposes

  • Understanding the depth of content is key for exam success:

    • Keywords in objectives indicate expected knowledge level (e.g., explain, summarize, compare)

    • Example question about USB 3 cable operating speeds

Summary of Upcoming Sections

  • Overview of computer ports and connectors

  • Types of cables covered will include:

    • USB cables: USB 1, 2, 3, Type-C, Type-A, Type-B, mini USB, micro USB

    • Video cables: HDMI, DisplayPort, DVI, VGA, Thunderbolt

    • Data transfer and storage: SATA, eSATA, IDE or PATA, SCSI, PATA, Lightning, serial cables, Molex cables

  • The section aims to equip future technicians with essential knowledge for effective technical work and troubleshooting.