Structure of floppy disk, Structure of CD – ROM?

 

Structure of floppy disk

• It is a Portable, inexpensive storage medium 
• It is made up of flexible plastic material coated with magnetic oxide 
• There is a sliding shutter at the top center of floppy disk. 
• There is a notch called write protect slot at the bottom of the floppy 
• It is generally labeled as DD or 2D 
• Data is stored in tracks and sectors 
• Each sector holds 512 bytes of data 
• It comes in to 5.25 inches and 3.5 inches. 

Structure of CD – ROM? 

• It is a Flat, round, portable metal discs with protective plastic coating 
• Disc diameter equals to 120 mm 
• Centre hole diameter of the disc is 15 mm 
• The area closed to the center hole is called clamping area, it is 26 mm to 33 mm wide 
• The data area is divided into three sectors table of contents, program area and read-out area. 
• Data are stored in pits and lands.