Storage Devices

Storage Devices

1. Magnetic Disk

   • Order of where data is stored
     • Disk Track Sector Block
   • Acuator arm / read/write arm reads and writes the disk
   • Data

2. Magnetic Tape

   • Slow
   • Serial, stored in one block
     • To read data you must go through from start to finish
   • Is magnetised
   • Advantages
     • Probably the cheapest form of storage per megabyte of storage
     • Can store large amounts of data - up to 1 Terabyte per tape cartridge
     • Can be set up to do the back up overnight or over the weekend
   • Disadvantages
     • Serial access so can be quite slow to access data
     • Need a special piece of equipment to record and read the data on the tape
     • The data may be corrupted if the tape is placed near a strong magnetic field e.g. a large speaker or magnet
   • Good for archiving files
     • Large organisations that need to back up their systems daily use these

3. Secondary storage is added to make the computer function more effectively.

4. Can be categorised into 3 groups:

   • Magnetic
   • Optical
   • Solid state

Images and files in the map