Chapter 10: Essential Peripherals ( A+ Study Notes)

A+

Study Notebook

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You can find my complete study notes in Google Docs format below: https://docs.google.com/document/d/1zcKLWfsns1tqzmXtVRJbcd9NqfaEcjifgIo-oJIbEgc/edit?usp=sharing

References:
M. MEYERS, 2019.  CompTIA A+ All-in-One Exam Guide. 10th ed.

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Chapter 10: Essential Peripherals

Common Ports

• Serial Ports (old devices connect mostly through serial connections. Using Standard 232 (RS-232 or DB-9) - 9-pin - D-shell male socket )

·         USB (Universal Serial Bus)

·         USB consists of:

·         USB Host controller, which is usually built into the chipset. And acts as an interface between the system and every USB device which connect to it.

·         Supports up to 127 USB devices

·         Sends commands and provides power to USB devices 

·         It is shared by every device plugged into it, as such power and speed reduces by each device connected into it 

·         Connected to USB host controller is USB root hub - which makes physical connection to the USB ports. 

·         Every USB root hub is a bus

·         USB 1.0

·         Low-speed - 1.5Mbps

·         Full-speed - 12Mbps

·         USB 2.0

·         High-speed - 480 Mbps

·         USB 3.0

·         Super-speed - 5Gbps

·         USB 3.1

·         Super-speed - 10Gbps

·         USB connector types: 

·         USB A (connects upstream towards the host controller e.g. PC)

·         USB B (connects downstream into USB devices) 

·         USB C - 24-pin 

 

·         USB Hubs - extends a single USB connection to two or more

·         FireWire Ports (IEEE 1394 (a/b)) - 400 - 800 Mbps 

·         Thunderbolt Ports (created by Apple and Intel)

·         Uses PCIe bus 

·         Thunderbolt 1 / 2 use Mini DisplayPort (mDP) connector

·         Thunderbolt 1 - 10 Gbps 

·         Thunderbolt 2 - 20 Gbps

·         Thunderbolt 3 uses USB Type-C

·         40 Gbps speed at half the power consumption of Thunderbolt 2

·         Can be made of copper or fiber 

·         Copper  max 3 meters

·         Fiber max 60 meters 

·         USB Type-C and Thunderbolt USB Type-C look same but aren’t same

• KVM Switches - allows usage of single mouse/keyboard/monitor to control multiple computers or vice-versa. 

• Good for server environments, data servers etc. 
• Sound 
• Computers record sound through a process called sampling. 
• Sampling - recording sound wave a set number of times per second
• Sampling rate - units of thousands of cycles per second or kilohertz (kHz)

• Computer sample in the range between 11 kHz - 192 kHz 
• 3 things need to be recorded to successfully translate sound into digital form of 1s and 0s: 
• Amplitude - loudness
• Frequency - high or low tone 
• Timbre - qualities that differentiate the same note from different instruments
• Bit depth of the sample  - amount of characteristics per particular sound captured 
• Mono vs Stereo 
• Recorded sound format 
• Compressed vs Uncompressed 

• PCM  (Pulse code manipulation) also known as WAV 
• MPEG-1, or Layer 3 codec, or Mp3
• AAC
• MIDI  is a text file 
• SPDIF (Sony/Philips Digital Interface) - connector which allows you to connect your soundcard to a 5.1 speaker. 
• Optical (square) 
• Coaxial (standard RCA connector)
• Video
• Multiple tracks compressed into one.
• Moving image and audio
• Compressed with codecs
• MPEG-2 Part 2 (e.g. DVD)
• H.264 / H.265 (e.g. Youtube)
• VP9 (e.g. Android)
• Wrapper/Container file: Compressed files get wrapped into a container file 
• AVI
• MOV
• MP4