Floppy 3.5' diskette

Last crawled date: 2 years, 3 months ago

The 3 ½-inch (90 mm) sizes of data storage and exchange, now with an external USB floppy disk drive. The core of the 3½-inch disk is the same as the other two disks, but the front has only a label and a small opening for reading and writing data, protected by the shutter—a spring-loaded metal or plastic cover, pushed to the side on entry into the drive. Rather than having a hole in the center, it has a metal hub which mates to the spindle of the drive. Typical 3½-inch disk magnetic coating materials are: DD: 2 µm magnetic iron oxide HD: 1.2 µm cobalt-doped iron oxide ED: 3 µm barium ferrite