Content

OS

🔗

Cache

Register

Main memory

Buses

HDD

Device controller

PCI

Polling

DMA

Synchronous(CS)

Asynchronous(CS)

Device Driver

CHS

LBA

Locality of reference

SSD

Interrupt handler

Overhead

metadata

OS

  • Cache
    • Def: a small, fast memory between the processor and the main memory. 💡
    • features 🌟
      • smaller than main memory
      • faster than main memory
      • a memory in the middle
      • less expensive types of semiconductor memories
    • app
      • provide fastest large size memory for CPU to reference(byte, word)
      • Get bytes, words from the main memory
  • Register
    • Def: a memory location embedded in CPU that can be accessed by other elements in CPU directly 💡
    • features 🌟
      • embedded in CPU
      • very fast. we can say the fastest memory device
    • app
      • store the data that can be operated by other elements in CPU
    • categories
      • PC(program counter)
      • IR(instruction register)
      • MAR(memory address register)
      • MBR(memory buffer register)

🍎Ⓜ️2️⃣

  • main memory
    • equivalent
      • RAM(random access memory)
      • primary memory(storage)
      • real memory
    • def: a large fast memory that stores data and programs that can be accessed directly by the CPU 💡
    • features 🌟
      • volitile
      • large and fast
      • random access
    • app
      • Store data and programs

Note: speed: register>cache>main memory

  • buses
    • Def: a set of wires for communication between devices and it contains protocols for data transfer operation 💡
    • features 🌟
      • Wire (H/W – hardware)
      • connection
    • app
      • communication in computer system
  • HDD
    • Hard disk drive
    • Def: is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage 💡

  • Device controller

    • equivalent
      • adapter
    • Def: a electronic component in an IO unit that helps deal with the digital communication logic between the device and other devices it connects to 💡
    • features 🌟
      • Electronic H/W(different from mechanical component which is device it self)
      • Adapt to connections
    • app
      • make divices can “speak” to other digital devices

  • PCI

    • Peripheral Component Interconnect
    • Def: a local computer bus interface(more like a standard) for attaching computer peripherals 💡
    • Other related concepts. 💭
      • PCI Express(PCIe)

  • polling

    • equivalent
      • busy waiting
    • Def: the process that computer or controller device waits for the an external device to check for its state(esp. readiness) 💡

  • DMA

    • Direct memory access
    • Def: a module controls the exchange of data between main memory and an I/O module. 💡
    • features 🌟
      • save CPU time
      • Slow than CPU

  • Synchronous(in CS)

    • Def: to describle a behaviour that makes a request to other things and then waits for the response. 💡
    • features 🌟
      • highly time-dependent

  • Asynchronous(in CS)

    • Def: to describe a behavioue that mekes a request to other things and do other things until getting the response. 💡
    • fearures
      • time-independent

  • Device driver

    • Def: device-specific code for controlling the device attached to a computer 💡
    • features 🌟
      • S/W --software
      • differs for different OSs

  • CHS

    • Cylinder Head Sector
      • Track: a ring section of the platter of a disk
      • Cylinder: stack of tracks that construct a cylinder
      • Head: device reads and writes data
      • Sector: cake slice of track
    • Def: a method for giving addresses to each physical block data on a HDD with 3 elements(C,H,S) 💡
    • features 🌟
      • earlier one

  • LBA

    • Logical Block Addressing

    • Def: a linear addressing scheme using integer index 💡

    • features 🌟

      • linear

  • Locality of reference

    • equivalent

      • principle of locality

    • Def: the tendency of processor to access a same set of data over a small period 💡

    • Other related concepts 💭

      • anticipatory I/O scheduler

  • SSD

    • solid state disk/ solid state drive
    • Def: a device using integrated circuit to store data persistently 💡
    • features 🌟
      • using NAND flash memory
      • no moving mechinal part
      • high random access speed
      • Light, low power, silent, reliable

  • Interrupt handler

    • equivalent
      • Interrupt service routine(ISR)
    • Def: is a special block of code associated with a specific interrupt condition in computer system. 💡

  • overhead

    • Def: the resources required to set up an operation

  • metadata

    • Def: data about data, a description and context of the data
    • App:
      • describle data
      • make controlling data easier