Chapter 3 Hardware

Computer and their components

Types of memory and storage

• Primary memory

  • RAM	ROM
    Random access memory	Read only memory
    used to store data during runtime of computer	used to store system information
    can read & write data	can only read data
    volatile (data gonewhen computer switched off)	non-volatile

  • RAM(Random Access Memory)

    • DRAM(dynamic RAM)
    • SRAM(static RAM) - faster than DRAM but also have lower capacity

  • ROM(Read Only Memory)

    • PROM(programmable read-only memory)
    • EPROM(erasable programmable read-only meomry)

• Secondary storage devices

  • HDD(Hard disk drives)
  • SSD(Solid state drives)
  • Optical media: CDs, DVDs and Blu-ray discs

Input and output devices

actuator

Laser printer, inkjet printer, 3D printer

speakers and microphones

screens, touch screens

virtual headsets

sensors

Embedded systems

Embedded systems involve installing microprocessors into devices to enable operations to be controlled in a more efficient way.

• pros: small in size; low cost; consume little power; fast reaction; simple interface
• cons: difficult to upgrade; open to hackers, virus, and so on; although interface appears to be simple, they can still be confusing in reality

Logic gates and logic circuits

NOT > AND, OR