1.1 Hardware and Communication Flashcards
HTTP
Hyper Text Transfer Protocol
FTP
File transfer Protocol
SMTP
Simple Mail Transfer Protocol
IMAP
Internet Message Access Protocol
DHCP
Dynamic Host Configuration Protocol
TCP
Transmission Control Protocol
UDP
User Datagram Protocol
IP Address
Internet Protocol Address
Internet
A network of networks that uses the internet protocols TCP/IP to link devices together
Handshaking
The agreement of protocols two devices will use to communicate, takes place through the transfer of a single byte of data
Protocols
The set of rules that govern how devices communicate, it is not possible for two devices to communicate without having the same protocols
Protocol stacks
When a packet is sent, there are many tasks that need to be completed before the packet arrives on time and whole. e.g. TCP/IP
TCP/IP stack
Is the stack used in most modern network transmissions.
What are the seven layers of TCP/IP stacks?
Application, Presentation, Session, Transport, Network, Data link, Physical
Give an example of something found on the Application layer?
HTTP or HTTPS or FTP
Give an example of something found on the Presentation layer?
ASCII or Encryption or PNG or MIDI
What happens in the Session layer?
Handshaking, e.g. Syn/Ack
Give an example of something found on the Transport layer?
UDP or TCP
What is found on the Network layer?
IP or routers
What is found on the Data link layer?
MAC or switches
What is found on the physical layer?
Cables
What does CPU stand for?
Central Processing Unit
What does the CPU do?
Carries out all mathematical and logical operations necessary to execute any given instruction.
ALU
Arithmetic Logic Unit
CU
Control Unit
Name the five different registers?
Program counter
Memory address register
Memory data register
Current instruction register
Accumulator
What does the ALU do?
The ALU is responsible for completing all calculation and logical operations.
What does the CU do?
Manages the execution of machine code by sending signals to the rest of the computer. It synchronises instruction by using the processors internal clock.
What does the Program Counter do?
The program counter stores the address of the next instruction that is to be executed
What does the Memory Address Register do?
The memory address register stores the location of the instruction or data to be fetched.
Where are currently running programs stored?
Short term memory, e.g. RAM
What does the Memory Data Register do?
The memory Data register stores the fetched instruction or data.
What does the Current Instruction Register do?
The current instruction register stores a copied version of the instruction that has just been fetched from memory, so that the MDR can be freed up.
MDR
Memory Data Register
MAR
Memory Address Register
PC
Program Counter
CIR
Current Instruction Register
ACC
Accumulator
What does the Accumulator do?
The accumulator stores the result of any equations (logic or mathematic) that the ALU has completed
Secondary Storage
Secondary storage stores all long term data that a computer needs like user files and operating systems
What secondary storage devices are commonly used in desktop computers?
Magnetic Hard drives
What secondary storage devices are commonly used in portable devices ?
Solid State Drives
What is Parallel Processing?
Parallel processing is when a CPU completes multiple fetch-decode-execute cycles at the same time
Fetch-Decode-Execute Cycle
Is a cycle that CPU’s use to complete tasks, they Fetch the instruction from memory, they Decode it into usable data, then they execute the instruction, each cycle happens very quickly
Busses
Transport data from the RAM to the CPU
Cache
Is memory that is placed between the processor and the main memory
Disadvantages of Cache:
Cost, Space
Advantages of Cache:
Faster, Efficiency
Name three kinds of Input Devices:
Keyboards, Pointing devices, Data-Entry devices
What is the purpose of Input Devices?
Allows data such as text, images, video or sound to be entered into a computer system
Name three kinds of Output Devices:
Monitor, Speaker, Printer
What is the purpose of Output Devices?
Allows data such as texts, images, videos and sounds to be outputted to the user from the computer system
What are the three types of secondary storage?
Optical, Solid State, Magnetic
Fragmentation
The Fragments of data within a storage device, these fragments take up more space
De-Fragmentation
The process of sorting out fragments of data into whole sections again. This saves the space the fragments were taking up
Should you De-fragment Solid State Drives?
No
Byte
Is a collection of 8 bits
Nyble
Is a collection of 4 bits
Word
Is the total number of bits that can be manipulated as a single unit by the CPU
