input, output devices & storage

• What are input devices?

  Devices that allow data entry
• What are output devices?

  Devices that present data to users
• What is a touch screen?

  A device that serves as both input and output
• What performance factors affect input and output devices?

  Speed, accuracy, cost, relevance to task
• What is the purpose of storage methods?

  To store information suited to its type
• How do optical devices read and write information?

  Using lasers to reflect or scatter light
• What does a pit represent in optical storage?

  A 0, by scattering light
• What does a land represent in optical storage?

  A 1, by reflecting light
• How are pits and lands arranged on a disc?

  In spiral tracks on the disc's surface
• What does CD stand for?

  Compact disc
• What is the primary use of CDs?

  To store small quantities of audio files
• What are the characteristics of CDs?

  Portable, easily damaged, limited capacity
• What does DVD stand for?

  Digital versatile disc
• What is the primary use of DVDs?

  To store digital videos
• How does Blu-Ray compare to DVDs?

  It has more than five times the storage
• How do magnetic devices represent binary information?

  Using two magnetic states: polarised and unpolarised
• What is the most common type of magnetic storage?

  Hard disk drives
• What are the characteristics of hard disk drives?

  High capacities, slow speeds, multiple platters
• What is the typical capacity range for hard disk drives?

  500GB to 5TB
• What is a disadvantage of hard disk drives?

  They can be damaged by movement
• When were magnetic tapes first used?

  In the 1950s
• What is a disadvantage of magnetic tape storage?

  It is space-consuming
• What is the typical storage capacity of floppy disks?

  1MB
• What are the characteristics of flash storage?

  Fast, compact, non-volatile
• What logic gates are used in flash memory?

  NAND and NOR
• How is information stored in flash memory?

  In blocks combined to form pages
• What is a primary disadvantage of flash memory?

  Higher cost per gigabyte
• What is a characteristic of solid state drives?

  They have no moving parts
• What is a disadvantage of solid state drives?

  Higher cost and limited lifespan
• What does RAM stand for?

  Random access memory
• What is the purpose of RAM?

  To store data and programs in use
• How does RAM compare to flash memory?

  RAM has higher access speeds
• What does ROM stand for?

  Read only memory
• What is a key characteristic of ROM?

  It cannot be modified once programmed
• What is the purpose of ROM?

  To store fixed sequences of instructions
• What is virtual storage?

  Storing information remotely for access
• Why is virtual storage becoming more popular?

  Due to increasing internet speeds
• What is a disadvantage of virtual storage?

  Limitations of network speed and high costs
• What is often the structure of virtual storage?

  An abstraction of multiple drives acting as one