Not the cases the CD came in though. You had to buy special cases that where compatible with your CD player. Handy, but it started to get expensive once you had more than 20 or so CDs.
Also, our early CD drives for our computer had this, except the caddy could be opened up and the CD inside changed. We had one caddy for the computer.
AFAIK it was an open question, if they were going the diskette way, or go with open discs. The polycarbonate plastic was deemed so tough, and of course it was cheaper to just produce the discs without a caddy, so they went with naked discs. IIRC.
Yep. It's too bad the CD format didn't specify this caddy, so that every commercial CD came in a caddy and was non-removable from it.
Wow, I never knew this. Can you give an example of such a system? My initial search has returned nothing.