Hacker News Reader

For people a little younger than me, there are both floppy disks and minidiscs here.

Minidiscs were used for data almost exclusively in Japan, they are small rewritable CDs in a plastic shell.

(I am the only person I know to have owned a Minidisc player.)

I also owned a couple minidisk players, a real underrated format.

A lot of those are not minidiscs, but 5.25" and 3.5" magneto-optical or discs inspired by them. (Minidisc is actually a small MO disc, btw).

In somewhat later material, DVD-RAM also shows up in caddies.