Peripheral Connections

CompTIA A+ Core 1 (220-1101) Reference Guide

Master the essential peripheral connections covered in the CompTIA A+ curriculum. From legacy ports to modern high-speed interfaces, understand speeds, specifications, and real-world applications.

USB Standards

2.0 to USB-C

Wireless

Bluetooth, Wi-Fi, RF

Display Ports

VGA to DisplayPort

Storage

SATA, eSATA, FireWire

Wired Peripheral Connections

USB (Universal Serial Bus)

USB 2.0

480 Mbps

Connector: Black or white

Use: Legacy devices, keyboards, mice

Power: 2.5W (5V, 0.5A)

USB 3.0 / 3.1 Gen 1

5 Gbps

Connector: Blue

Use: External drives, high-speed devices

Power: 4.5W (5V, 0.9A)

USB 3.1 Gen 2 / USB 3.2

10 Gbps

Connector: Teal

Use: High-performance storage, video

Power: Up to 100W with PD

USB Type-C

Up to 40 Gbps

Connector: Reversible, oval

Use: Modern devices, Thunderbolt support

Power: Up to 100W with USB-PD

Thunderbolt

Thunderbolt 1 & 2

10-20 Gbps

Connector: Mini DisplayPort

Use: Professional video, external displays

Daisy Chain: Up to 6 devices

Thunderbolt 3 & 4

40 Gbps

Connector: USB-C

Use: eGPUs, high-speed storage, 4K displays

Power: Up to 100W delivery

Legacy Connections

PS/2

Legacy

Connector: 6-pin DIN

Colors: Purple (keyboard), Green (mouse)

Use: Legacy keyboards and mice

Serial (RS-232)

Legacy

Connector: DB-9 or DB-25

Speed: Up to 115.2 Kbps

Use: Modems, industrial equipment

Parallel (LPT)

Legacy

Connector: DB-25 female

Speed: 2 Mbps

Use: Legacy printers, scanners

Display Connections

HDMI

Up to 48 Gbps

Types: Standard, Mini, Micro

Use: Digital video + audio

Max Resolution: 8K@60Hz (HDMI 2.1)

DisplayPort

32.4 Gbps

Connector: 20-pin, locking

Use: High-resolution displays

Features: Daisy-chaining, MST

DVI

9.9 Gbps

Types: DVI-D, DVI-A, DVI-I

Use: Digital/analog video

Max Resolution: 2560×1600@60Hz

VGA

Analog

Connector: Blue, 15-pin

Use: Analog video only

Max Resolution: 2048×1536@85Hz

Audio Connections

3.5mm TRS/TRRS

Analog

Colors: Pink (mic), Green (line out), Blue (line in)

Use: Headphones, microphones, speakers

Types: Stereo, mono, with mic

Optical (TOSLINK)

Digital

Connector: Fiber optic

Use: Home theater, digital audio

Benefit: No electrical interference

Wireless Peripheral Connections

Bluetooth

1-3 Mbps

Range: 30 feet (Class 2)

Use: Keyboards, mice, speakers, headsets

Frequency: 2.4 GHz ISM band

Wi-Fi (802.11)

Up to 9.6 Gbps

Standards: a/b/g/n/ac/ax

Use: Wireless printers, cameras, IoT devices

Range: 100-300 feet

RF (Radio Frequency)

Varies

Use: Wireless mice/keyboards with USB receivers

Range: 30-100 feet

Frequency: 2.4 GHz or proprietary

Infrared (IR)

Legacy

Use: Remote controls, older PDAs

Range: Line-of-sight, 3-6 feet

Limitation: Requires direct line of sight

Storage & Media Connections

SATA

6 Gbps

Use: Internal HDDs, SSDs, optical drives

Versions: SATA I/II/III

Cable Length: Up to 1 meter

eSATA

6 Gbps

Use: External storage devices

Status: Largely replaced by USB 3.x

Cable Length: Up to 2 meters

FireWire (IEEE 1394)

800 Mbps

Use: External drives, video equipment

Types: FireWire 400, 800

Status: Legacy, replaced by USB/Thunderbolt

SD/microSD

Up to 985 MB/s

Use: Cameras, phones, printers

Types: SD, SDHC, SDXC, microSD variants

Capacity: Up to 2TB

CompTIA A+ Study Tips

Visual Recognition

Know connector shapes and colors
Understand pin counts and orientations
Recognize legacy vs. modern ports
Practice with physical hardware when possible

Speed Memorization

USB 2.0: 480 Mbps (half a gigabit)
USB 3.0: 5 Gbps (5x faster than USB 2.0)
Thunderbolt 3: 40 Gbps (fastest consumer port)
Remember power delivery capabilities

Common Exam Traps

Don’t confuse USB 3.0 vs 3.1 vs 3.2 speeds
Remember USB-C supports multiple protocols
Know which connections carry power
Understand backwards compatibility

Practical Applications

Match connection types to device requirements
Consider cable length limitations
Know when to use adapters/converters
Understand power requirements for devices