OS

I/O types

  1. programmable
    • CPU sends data to device
    • CPU polls the device, whether it’s ready/busy
  2. interrupt-driven
    • interrupts instead of polling
    • a lot of time to process interrupt
  3. direct memory access (DMA)
    • controller processes request instead of CPU
  4. premapped
    • physical RAM addressing
  5. fully mapped
    • logical RAM addressing