Back in the 80's we used to backup an IBM business computer to a stack of 8-inch floppies - 'diskettes' as IBM called them. It could write to up to 16 of these in one operation, loaded into two plastic cartridges. A 'jukebox' inserted each diskette into the drive in turn, replaced it after writing, and slid the cartridge along to the next slot.

The early Macintoshes used to get more data on their 3½-inch floppies by rotating them at variable speed so that more bits could be recorded on the outer tracks. This made the floppies unreadable on PCs.