Flashcards
1. Hardware and Communication
Cards in this deck (101)
- 1Section Key Words- Semiconductor
- Memory
- Storage
- RAM
- CPU
- Cache
- SSD
- 2Computer Parts
- 3Von Neumann Architecture
- 4Semiconductor Properties- Conductor & Insulator
- Alternates with changes in input voltage
- Generally silicon
- 5Semiconductor Uses- Used in SSDs ∵ they can let signals in and out selectively to store or move data
- 6Storage Properties- Non-volatile (Permanent)
- Stores saved data and files
E.g. SSD or Hard Drive - 7Memory Properties- Volatile (Temporary)
- Stores active programs and data
E.g. RAM, Cache
- 8SSDSolid State Drive:
- Storage
- Non-Volatile - 9HDDHard Disk Drive:
- Storage
- Non-Volatile
- 10Random Access Memory (RAM) - Properties- Type of memory
- Stores active data and programs currently on CPU
- Slower than cache but larger
- 11Cache - Properties- Type of memory
- Stores freq. data used by CPU
- Split into 3 levels - 12Levels of Cache1. Very fast ∵ embedded in CPU
2. Slower with > capacity
3. Speeds up 1 & 2, shared by all cores
- 13Parallel Processing- Used ∵ limitations of single-core size
- Splits processes --> sub-processes
- Speeds up processing
- Cannot be used 100% of the time - 14Parallel Processing (Requirements)- OS that supports it
- Multiple cores (2, 4, 6, 8 e.t.c)
- Process that supports it - 15More Key Words- ALU
- PC
- CU
- ACC
- MAR
- Buses - 16CPUCentral Processing Unit
- 17RegistersSmall/fast/temporary memory typically used by things other than the main memory
- 18CUControl Unit
- Handles ctrl signals
- Manages input and output
- Control bus - 19ALUArithmetic Logic Unit
- Does maths
- Handles logic ops - 20ACCAccumulator
- Stores each ALU result (like a flowchart) for multi-step sums - 21PCProgram Counter
- Keeps location of next process
- Passes info to MAR - 22MARMemory Address Register
- Gets address from PC
- Loads the info
- Address bus - 23MDRMemory Data Register
- Stores the data from the location stored by MAR
- Data bus - 24CIRCurrent Instruction Register
- Keeps current instruc for exec
- Gets from MDR - 25IBRInstruction Buffer Register
- Stores instructions for later - 26Decode unit- Decodes op code to understandable instructions
- 27Buses- Data -> via these
- 28Data Bus- Carries the data
MDR <--> - 29Address Bus- Carries data's address
MAR --> - 30Control Bus- Carries ctrl commands from CPU ∴ coordinates computer
CU <--> - 31Machine codeSeries of Op codes and operands written in binary
- 32Op CodesOperation codes
- Instructions in machine code - 33Operands- The data to be manipulated
- Always w/ op code - 34Optical Storage - Function- Laser burns 'pits' in disk ∴ writes
- Reflection detects pits and lands ∴ reads - 35Optical Storage - Uses- DVD
- CD
- Blueray
Movies & audio: media - 36Optical Storage - Pros and consPros:
- Capacity, Size, Cost ∴ good for HD data
- Durability > HDD
- Portable
(Capacity: 650MB - 128GB)
Cons:
- Easily scratched - 37Magnetic Storage - Function- Disk always spinning
- Arm changes state of dipoles ∴ write
- Reader detects state ∴ read - 38Magnetic Storage - Uses- HDD
Storing:
- Programs
- OS
- Server backups - 39Magnetic Storage - Pros and consPros:
- Speed > OD
- Capacity > OD
(Capacity: 500MB - 4TB)
Cons:
- Damaged by magnets - 40Portable External Storage Devices - Function- Known as EEPROM
- Keeps charges with gates ∴ non-volatile memory
- Semiconductors - 41EEPROMElectronic Erasable Programmable Read-Only Memory
- 42Portable External Storage Devices - Uses- Flash drives
- SSD - 43External Portable Storage Devices - Pros and consPros:
- Speen > HDD ∵ no motion
Cons:
- Cost > HDD
- Space < HDD - 44Fragmentation- Related data (file contents) is scattered across hard-drive
- Slower ∵ more movement is needed - 45Defragmentation- Reorganising drive to put related data (files) together
- Faster ∵ less movement is needed ∴ data is contiguous
- Not used in SSD - 46RAIDRedundant Array of Independent Disks
- 47RAID 0 - Function- Stripes (splits) data
- 2 drives
- 48RAID 0 - Pros and consPros:
- Fast (avoids bottlenecking)
Cons:
- If one drive is lost, data make no sense ∵ striping - 49RAID 1 - Function- Mirrors data
- 2 drives
- 50RAID 1 - Pros and consPros:
- Data safe if one drive lost
Cons:
- Speed < RAID 0 - 51RAID 3-6 - Function- Stripes data with parity
- >= 3 drives
- 52RAID 3-6 - Pros and consPros:
- If a drive fails, a new drive can be inserted and data is restored using parity
Cons:
- Only 3/4 space can be used ∵ 1/4 is used by parity - 53Basic Network Terms- IP
- Packet
- Router
- Hub
- Switch
- Firewall
- LAN - 54IPInternet Protocol
- Prepares, sends & recieves packets
(sender's address, recipient's address, data) - 55Packets- Contain data & other needed info
- Sent by IP over the net to the recipient - 56Router- Connect networks
- Routes packets over networks
- 57Switch- Joins computers in a network
- 58HUb- Common connec point in a network
- 59Peer to peer network- Client joined with client
- No server
- Wired
- 60Client-sever network- Mult clients connect to server
- Files stored on server
- 61LANLocal Area Network
- Computers joined locally
- Within building
- 62WANWide Area Network
- Connection of LANs
- 63Network TopologiesDiff configs of networks:
Bus, Star, Mesh, Tree, Ring, Point to point - 64Network Topologies (Diagr)
- 65NICNetwork Interface Card
- Connects computer to wired network
(Wired)
- 66WNICWireless Network Interface Card
- Connects computer to wireless network
(Wireless)
- 67NATNetwork Address Translation
- Network device gives public address to private machine - 68More Key Words- Protocol
- TPC/IP Stack
- HTTP
- DHCP
- UDP
- SMTP - 69Protocol- Global rules
- Allow communication - 70Networking Standards (Hardware)- Standard equipment must interoperate
- Internationally agreed
- Allows end user to use equipment from anywhere - 71TCP/IP StackHandles data over web
4 Layers:
Application layer, Transport layer, Networking layer, Data link layer - 72Application layerUses app-based protocols
(HTTP, FTP, SMTP...)
Connec. to Transport layer via port - 73Transport layer- End-to-end connections
- Handles connection errors
(TCP, UDP) - 74Networking levelGives data routing paths
(IP, DHCP) - 75Data Link LayerEncodes and decodes data
Has two layers:
Media Access Control (MAC), logical link control - 76HTTPHyperText Transfer Protocol:
- Transporting HTML files
- Uses Uniform Resource Locators (URLs)
- Data isn't recorded
- Port 80 - 77FTPFile Transfer Protocol:
- Uploading and downloading
- Data is recorded
- Port 21 - 78SMTPSimple Mail Transfer Protocol:
- Sends + Receives
- Client uses send only
- Ports 25 & 587 - 79IMAPInternet Message Access Protocol:
- Storing and Receiving
- Mult clients --> same mailbox - 80DHCPDynamic Host Configuration Protocol:
- IP networks
- Gives device dynamic IP
- Automatic - 81UDPUser Datagram Protocol:
- Minimal features
- Unreliable
- No error checking & resending of packets - 82Handshaking- Agree on protocols
- Either agreed or denied
- Communication cannot happen without this - 83What is Optical Character Recognition (OCR)?Scans handwritten text -> editable document
Postprocessing - after text has been scanned - 84What are the uses of OCR?Editing a printed document
- 85What are the limitations of OCR?- Unable to read bad handwriting
- Requires a scanner - 86What is Optical Mark Recognition (OMR)?Reads marks on a multi-choice form
Postprocessing - 87What are the uses of OMR?Quickly marking multi-choice questions in bulk
- 88What are the limitations of OMR?- Predetermined question paper
- Reads inaccurate marking wrong
- Requires scanner - 89What is Magnetic Ink Character Recognition (MICR)?Special reader detects the magnetism of the ink
Can read writing even if it has been written over - 90What are the uses of MICR?Cheques + other important documentation
- 91What are the limitations of MICR?Requires special ink and reader
- 92How do touchscreens work?Using a grid to detect user's input
Coordinates are sent to the OS - 93What are the uses of touchscreens?Tablets, laptops, smartphones
- 94What is Voice Input?Detects user's vocal input and discerns what is asked
- 95What are the uses of Voice Input?Smartphones & translation apps
- 96What are the limitations of Voice Input?- Very inaccurate with background noise
- Has set amount of commands - 97What is Vocabulary Dictation?Takes speech input and converts to text (Speech to text)
Specialist vocab can be introduced - 98What are the uses of Vocabulary Dictation?Creating text documents via speech
- 99What are the limitations of Vocabulary Dictation?- Very inaccurate with background noise
- Has set amount of commands - 100What is Voiceprint Recognition?System saves a sample of a person's voice and digitises it
System then takes another input and compares it to the sample - 101What are the uses of Voiceprint Recognition?Login and other security systems
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- A Level Computer Science ((AS) Unit 1: Fundamentals of Computer Science ) Flashcards on 1. Hardware and Communication, created by Scott Jones on 31/07/2019.
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- Scott Jones
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