Machine-readable Medium

In telecommunications and computing a machine-readable medium (automated data medium) is a medium capable of storing data in a format readable by a mechanical device (rather than by a human).

Examples of machine-readable media include magnetic media such as magnetic disks, cards, tapes, and drums, punched cards and paper tapes, optical disks, barcodes and magnetic ink characters.

Common machine-readable technologies include magnetic recording, processing waveforms, and barcodes. Optical character recognition (OCR) can be used to enable machines to read information available to humans. Any information retrievable by any form of energy can be machine-readable. Examples include:

• Acoustics
• Chemical
  • Photochemical
• Electrical
  • Semiconductor used in volatile RAM microchips
  • Floating-gate transistor used in non-volatile memory cards
  • Radio transmission
• Magnetic storage
• Mechanical
  • Pins and holes
    • Punched card
    • Paper tape
      • Music roll
    • Music box cylinder or disk
  • Grooves (See also Audio Data)
    • Phonograph cylinder
    • Gramophone record
    • DictaBelt (groove on plastic belt)
    • Capacitance Electronic Disc
• Optics
  • Optical storage
• Thermodynamic