Higher Computing

Solid-State Devices

Features

  • Small and contains no moving parts, example include flash cards and USB flash cards(memory stick)
  • Both of these types contain the same type of backing storage medium, flash ROM
  • Difference between them is that they use different interfaces to connect to a computer or peripheral


Uses

Flash RAM is used where there is a constant supply of power, e.g car radios/ CD-players

Flash ROM is used:

  • in ROM BIOS: so that input and output settings can be updated easily
  • in Compact Flash and Smartmedia cards, where they are used to store digital camera photographs
  • in Memory Sticks on MP3 players
  • in the memory cards used for games consoles


Advantages

  • Small and makes no noise - fit inside cameras, on key-rings and in watches
  • Robust -ideal for wearing and are unaffected by vigorous movement due to no movement parts
  • Use less power than hard disk drives
  • Replaces floppy disks as they can fit in almost any modern computer
  • USB flash memory is used for security applications - one type has fingerprint recognition


Disadvantages

  • More expensive, per megabyte of storage, than a hard disk
  • Flash chips generally have a limit to the number of times they can be written to, normally between 100k and 300k write cycles


Development trends

  • Increased capacity
  • Increased read and write speeds
  • Reduced physical size
  • Lower cost per unit of storage


Increasing interface speeds and wireless communication

Two developments in interfaces are to:


  • Increase the speed at which the interface allows the peripheral and computer to communicate
  • Allow wireless communication between the peripherals and the CPU. For example using WiFi and Bluetooth