The -ette in cassette and diskette is a diminutive suffix. Cassette means little box. Casse is French for box. And thus Diskette means little disk, not disk in a protective case. IBM introduced the term to mean floppy disks smaller than their 8” floppy disks
Cassette is a French word, diskette is not. It even says that in your links. IBM used the word for the 8in floppies too. It’s a portmanteau of disk and cassette because IBM already made hard drives and these were portable and looked a little like a photography cassette.
No one is short for discus and the other is short for diskette.
Disk comes from the Greek word Diskos. And Disc from
the French word Disque. Edit: You were right it comes from Latin DiscusDiskette means little disk. Floppy disks existed before diskettes.
Diskette comes from cassette which had been used in photography long before describing tapes and just meant that it had a built in protective case.
The -ette in cassette and diskette is a diminutive suffix. Cassette means little box. Casse is French for box. And thus Diskette means little disk, not disk in a protective case. IBM introduced the term to mean floppy disks smaller than their 8” floppy disks
https://www.etymonline.com/word/cassette
https://www.etymonline.com/word/diskette
Cassette is a French word, diskette is not. It even says that in your links. IBM used the word for the 8in floppies too. It’s a portmanteau of disk and cassette because IBM already made hard drives and these were portable and looked a little like a photography cassette.