This little felt thing there is just to avoid too much friction from building up with the plastic or to keep it slightly separated from the case, but that's it. That's all there was to those things called floppy disks.

这种毡制品的目的是避免,由塑料组成所产生的摩擦力,或者保持稍微的距离，这就是我们要说的,软盘的全部内容。

哈佛公开课 - 计算机科学课程节选