Floppy and Removeable Media Drives

Floppy drives are similar to hard drives except that the r/w head touches the recording material and it is open to the environment.

This means that the rotational speed is much slower and the density of the material is lower.

Floppies come in several sizes and densities.

Size	capacity	case	Media
8"	180K	Plastic Sleave	Iron Oxide
5 1/4"	180K / 360K	Plastic Sleave/hub	Iron Oxide
5 1/4"	1.2M	Plastic Sleave/hub	Chromium Oxide
3 \275"	720K / 1.4Meg	Rigid Sleave/Metal Hub	Iron Oxide / Chromium Oxide

Early floppy disks used iron oxide and were all plastic and often only recorded on one side. This resulted in the regions that represented bits of data to be large. Also, the tracks had to be wide and far apart to compensate for wear on the plastic hubs. 3 \275" disks adapted a metal hub that provided a timing hole and a rigid non-wearing center which allowed more closely spaced tracks and resulted in higher data density. With the change of magnetic media to a chromium based material, the size of the bit region was smaller and thus packed closer together. com and of data to bcaused data to be r8", 5 1/4", and 3 ½" The two smaller disks also come in multiple densities. Using different recording material allows this increase. The 3 ½ " also comes in a quad density (2.8M) format which never became popular.

Another popular media is the zip drives which are advanced version of the floppy.