[OS]Computer System Overview

Computer Hardware

• Processor
  • CPU
  • GPU
• Memory
  • RAM, ROM
  • HDD, SSD
• I/O Device
  • Keyboard, Mouse
  • Monitor, Printer

Processor

Central Processing Unit(CPU)

• Processing unit
• Control unit

Register

• Memory inside the processor
  • Store the data that the processor will use
  • Fastest memory on your computer
• User-visible register
  • DR, Data Register
  • AR, Address Register
• User-invisible register
  • PC, Program Counter
  • IR, Instruction Register
  • ACC, ACCumulator
  • MAR, Memory Address Register
  • MBR, Memory Buffer Register

Operating Systems and Processor

• Assigning and managing tasks to process to the processor
  • Process creation and management
• Control the program’s processor
  • Manage processor usage times for programs

Memory

• Memory Type
  • Register
  • Cache
  • Main memory
  • Disk

Main memory

• Store programs and data that the processor will perform
• Primarily use DRAM
  • Large capacity, low price
• Reduce disk I/O botleneck

Cache

• Memory inside the processor(L1, L2 cache etc)
  • Fast, expensive
• Reduce main memory I/O botleneck

Cache works

• Cache hit
• Cache miss

Locality

• Spatial locality
• Temporal locality

Operating Systems and Memory

• Memory Allocation and Management
• Virtual Memory Management

System Bus

• The physical path through which hardware sends and receives data and signals
  • Data bus
  • Address bus
  • Control bus

I/O Device

Operating Systems and I/O Device

• Managing device drivers
• Interrupt Handling
• File and disk management

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Reference

Computer System Overview