Magnetic and Optical Storage Devices

In digital computing, data is represented by Bits

Storage means storing the on/off state

https://www.tinkercad.com/things/8BtgLiyfAbH-4-bit-storage

Magnets have two polarity, North and South

Each bit on magnetic medium is a very small magnetized region, either in S or N, representing 0 or 1

Read: using sensor to detect the polarity of that "dot"

Write: use electromagnet to magnetize the region

Data is stored as pits and land

Read: Laser shine on the region and a sensor detects if it is reflected (land) or not (pit)

Write: Laser burns on the surface to form the pits (that's why CD-ROM writing program is called CD Burner)

Since the pits is formed by burning, optical disc are usually Read Only or Write Once

No mechanical moving parts

Data stored on the ICs

Most portable compare to others