USB Technology Explained

• A PC consists of components that communicate with each other
• Understanding connection interfaces and connectors helps to efficiently install, upgrade, and replace PC peripherals

Personal Computers

• Components are split into those handled by the user (peripherals) and those damaged if exposed
• Peripheral devices manage input (keyboard, mouse) output (monitor, speakers), or storage
• Internal components are housed in the system case/chassis, including the motherboard, CPU, memory, adapter cards, disks and PSU
• Tower cases are designed to stand vertically on a desk or floor

All-In-One PCs

• Internal components are within a case that is also a monitor

Tower Cases and Front Panels

• Side covers are removable, sometimes secured with screws, clips, or anti-tamper mechanisms; system documentation is essential
• Front panels provide removable media drives, power switches, and LEDs, and may require side panel removal for access

PC Rear Panel Access

• The rear panel offers PSU sockets with a fan exhaust, which should not be obstructed for cooling
• Cutouts aligned with the motherboard's I/O ports allow the connection of peripherals
• Adapter card slots allow cables to connect I/O ports
• Uncovered slots disrupt airflow, causing overheating and dust accumulation

Peripheral Devices

• I/O ports enable device connection via peripheral cables
• Some ports are device specific, like graphics ports for monitors
• Ports are on the rear or front of the PC, either on the motherboard or as an expansion card

Interfaces, Ports, and Connectors

• Hardware Port: External connection point for a bus interface to transfer data
• Connector: Part of a peripheral cable inserted into a port with the same shape
• Keying: Asymmetric design to prevent incorrect insertion

Binary Data Storage and Transfer Units

• Computers process binary data where each bit has a value of one or zero
• Storage is measured in bytes (B), multiples of eight bits
• Transfer rates are measured in units per second
• 1000 bits/bytes = Kilobits/Kilobytes (Kbps or KBps)
• 1000x1000 bits/bytes = Megabits/Megabytes (Mbps or MBps)
• 1000x1000x1000 bits/bytes = Gigabits/Gigabytes (Gbps or GBps)

Universal Serial BUS (USB) Cables

• USB is a standard means of connecting peripherals categorized into classes like human interface, storage, printer and audio
• Host Controller: Manages a USB and its connections
• There could be up to 127 connected devices per controller
• PC motherboards typically feature multiple controllers with a few ports each to share bandwidth

USB Standards

• Every USB version offers enhanced data rates and new connector form factors
• USB 2.0 HighSpeed: Data rate of 480 Mbps, half-duplex
• USB 3.x: Introduced new connectors and full-duplex transfer rates

USB Transfer Rates

USB Controllers

• Feature two sub-controllers for SuperSpeed and legacy devices, ensuring older devices do not decrease SuperSpeed

USB Connector Types

• Type A: Connects to the host and shaped like flat rectangles with the USB symbol facing up
• Type B: Connects to larger devices like printers, square shape with beveled top
• Type B Mini: A smaller connector for older digital cameras

Type B Micro

• Updated connector for smaller devices like smartphones and tablets, distinctively flatter

USB 3

• USB 3 connectors have additional signaling pins and are blue
• USB 3 Type A connections are compatible with USB 1.1 and 2.0 connections
• Type B and Micro Type B connections are not

USB-C

• USB 3.1, compact, reversible design for a consistent hardware interface stronger than mini/micro designs
• USB-C is interchangeable, or used with USB-A or B converter cables

USB Cable Lengths

• USB: LowSpeed - max 3m, FullSpeed/HighSpeed - max 5m, 3m is recommended for SuperSpeed

USB Power

• USB-A and C can charge connected device
• Standard USB: 4.5 W
• Power Delivery (PD): 100 W, specific connectors and cabling

HDMI and Display Port Video Cables

• USB does not support video
• Video cables provision high video bandwidth demanded by video

Video Cable Bandwidth

• Resolution: Horizontal x Vertical pixels e.g 1920x1200 (HD) or 3840x2160 (4K)
• Speed: Hz or Frames Per Second (fps)
• Example: Uncompressed HD at 60 fps 4.5 Gbps and 4K at 60fps is 8.91 Gbps

Display Artifacts

• Refresh rate should match the frame rate or be divisible to avoid issues
• For example, 60fps should be paired with 120 hz

Computer Displays

• LCDs use thin film transistor (TFT)
• Colour LCDs use cells with filters to make red, green and blue
• Each pixel varies with transistor
• LED illuminated panel array

LCD/TFT

• Referred to as Flat panel
• LED displays have backlight
• Premium flat panels are OLEDs
• OLEDs have better contrast and color fidelity

High-Definition Multimedia Interface (HDMI)

• HDMI: Most popular video interface consumer electronics, gaming and Blu-Ray, also monitors
• Feature: Video, audio, and control features plus digital content protection (HDCP) now 4K, 8K
• Compatibility: Monitor refresh rate can match the video source frame
• HDMI: support audio if device video card has chipset

HDMI Connectors

• Full Type A, mini Type C and Micro Type D are available beveled

HDMI Cable

• Rated: Standard Category 1 or High Speed Category 2 cable
• High Speed cables support, lengths with 4K, 60 Hz refresh
• HDMI version 2.0 and 2.1 Cables: Premium (18 Gbps) and Ultra (48 Gbps)

DisplayPort Interface

• HDMI consumer electronics companies royalty to use
• DisplayPort royalty free
• Video Electronics Standards Association (VESA): PC graphics adaptors, supports HDMI
• DP++ and MiniDP/mDP connector keyed

DP++

• Bandwidth bonded to 4 Lanes.
• Bitrate per lane: 2.7 Gbps
• Supports daisy chaining multiple monitors from single source

Thunderbolt Interface

• Thunderbolt and Lightning interfaces associated with Apple and Windows and Linux PCs
• Thunderbolt doubles as display and peripheral

Thunderbolt Speeds

• Replaces MiniDP as display
• Monitor with DisplayPort will connect a computer Thunderbolt port using a suitable adaptor cable.
• Version 2 of standard supports 20 Gbps for daisy chaining like DisplayPort by daisy-chaining

Thunderbolt and USB-C

• Thunderbolt version 3 has USB-C ports,connectors,cabling
• Cables available to connect Thunderbolt 1 or 2 devices to Thunderbolt 3 ports.
• USB plugged into Thunderbolt 3 port will work
• Thunderbolt will not work on regular USB

Power

• Thunderbolt 3 supports 40 Gbps for short, high-quality cables up to 0.5m
• Not all USB-C ports support Thunderbolt 3., check Flash icon

Lightning Interface

• Apple iPhone/iPad uses proprietary reversible Lightning cable
• Only found on Apple mobiles, use a suitable lighting or USB cable to connect to a PC

SATA Hard Drive Cables

• Both internal and external

Serial Advanced Technology Attachment ( SATA)

• Standard way of connecting internal PC storage devices
• SATA: 1m cables with compact 7 pin connectors, Host adaptor support
• SATA Data = Does not supply power, 15 ping connector power device

SATA Standards

Molex Power Connectors

• Legacy devices connect to PSU via a Molex, white and clear with 4 pins
• Molex Wire Insulation rep DC voltage - Red 5 VDC, yellow 12VCD, black ground

External SATA

• (eSATA) is peripherals drive connecting 2m cable, internal SATA cable will not work for connection
• (eSATAp) is non-standard, used by vendors supports both USB and SATA but the external drive market is dominated by the USB interface