It was also cool because the activity would blink purple (orange + blue) during writing. This set it apart when blue LEDs were all the rage.
some sort of feedback for rotation angle maybe?
5-1/2: "floppy" plastic outer shell with a rectangle cutout across the disc, and a circle cutout so the disc could be squeezed/grabbed and then rotated. Stored in a paper sleeve to protect from scratching, all those were usually in a plastic case that held 10-100.
3-1/2: hard outer shell, metal exposed ring/hook in the middle, spring-closing door to protect from scratching. These had gone from ~360kb to 1.44mb (4x increase) and space hadn't bloated out yet. They were durable enough not to bend, and the protective door meant it was semi-dust/sand-proof.
Then along came CD'd... jewel cases, but you're carefully handling the actual media (ie: that magnetic disc/vinyl "record" from within the 5-1/2 floppy).
Caddies gave you the feel and protection of the 3-1/2 hard case disks, and were actually pretty useful if you had like a 6-CD encyclopedia set (eg: Encarta 2003 - https://news.microsoft.com/source/2002/06/27/microsoft-encar...).
You'd generally install a 50-100MB program and have to swap CD's depending on what program you had open (or what it was asking for). Even! There were IIRC 3-disc changer drives (like car audio) where you could load up a cartridge and switch (slowly) between discs 1, 2, and 3.
In some cases they were really useful! We had one with like a 20-slot Rolodex style storage box and you could load up the caddies (and type labels!) and keep the optical media safe from grubby kid's hands.
Zork, Myst, 7th Guest, Encarta, Clip Art bundles, font bundles... at a time when Nintendo was the contemporaneous technology, switching "cartridges" to whatever you were working on was an incredibly efficient use of space and money compared to how expensive hard drives were!
One theory I've seen is that caddies were developed in part to protect valuable data CDs from accidental damage, and faded in popularity as software became more affordable. Early multimedia software could be quite expensive, with some titles running into the hundreds of dollars.
Might be a good idea to preserve a known-working distro for some old PC, especially for discontinued or less-used architectures. Just saw a discussion the other day about finding 32-bit Debian for an old laptop.
I don't know how it ended up with later generations, but all the CD-R and DVD-R discs that I thought I had archived everything on became entirely unreadable after something around 7 to 8 years.
That said, the end result is pretty cool, if hard to photograph.
[1] https://hackaday.io/project/186303-burning-pictures-on-a-com...
https://debugmo.de/2022/05/fjita-the-project-that-wasnt-mean...
I assume this isn't possible with a DVD/bluray due to the much much smaller pits.
But I can't actually imagine what it would look like. Sounds amazing though!
The challenge (as I saw it) was that the drive has the option to toggle the state of the laser every sector, effectively letting it invert all your data if it wants to. To have control of the laser state, you need to be able to do perfect predictions if the drive will toggle or not.
Any unpredicted bit leads to the laser state toggling and the image being ruined.
It was really slow, but it did work.
See https://pilabor.com/blog/2022/10/audio-cd-ripping-hardware/
Hell, I'm not even sure if it's plugged in at the moment, I may have unplugged it to plug in another hard drive...
Luckily blurays are still somewhat cheap in Japan so I stock up when I visit. Stored properly they should outlive me.
Hopefully some of the copies live on after your death. Optical does well, but I've seen reasonably treated cd-rs degrade, and well treated pressed cds decay. Sometimes some mistake in production takes years to become apparent, but results in a fixed lifetime below the estimates.