So it's no wonder that ATAPI killed off SCSI CD drives in PCs. Since it _was_ SCSI, it really just killed off having to buy an extra host bus adapter card to send the same command set.
Sometimes that stuff could get pretty baroque. Back in the day I had a 20 MB HD for my Atari 8 bit computer, which involved an adapter from the Atari proprietary bus to SCSI/SASI, then a second adapter from SCSI to the MFM HD interface. You needed one of the custom DOSes to make use of it, as the standard Atari DOS had never envisioned things like hard drives.
At that point I didn't even want plug'n'play or hotplug because getting something set up once was enough for you to never desire to change it.
Like the old saying goes, "there are valid technical reasons that demand that you sacrifice a black goat here and there to your SCSI chain".
UAS is yet another variant of passing SCSI commands through USB.
Before(?) SAT, there was Cypress' ATACB for the same purpose: https://www.cypress.com/documentation/datasheets/cy7c68300c-...
I had a bad disk once and whatever happened affected the drive head. This of course meant that every other disk I had was then similarly corrupted. I know people that used many Zip drives and were quite happy with them, but I never trusted Iomega again after that.
We can say same of DATA
"Dicussed, Archived, Translated, Attributed (Falsely)"
So before ATAPI we still didn't buy a specific CD-ROM interface card to connect CD-ROM drives. We just bought a sound card that had the CD-ROM interface we needed. You just had to make sure you bought the right CD-ROM connectivity for your sound card.
My first PC was a used 486DX in the mid-90s, and it had a Sound Blaster 16 (ISA) with the IDE connection on it for a CD-ROM drive. However, the motherboard also had its own dedicated primary and secondary IDE channels already, so it seemed simpler to just use those when I bought myself a CD-ROM drive, and avoid whatever hoops would have to be jumped through to make the sound-card-connected one work.
Nowadays it's all gotten boring, all we can do is rip the digital audio data through the operating system and write it to the sound card.
With the exception of the TV out those cards were a terrible investment though. CPUs went from Pentium 120Mhz to Athlon 1000Mhz within 5 years and the playback software got optimized massively as well (CyberLink PowerDVD was a big success since it could enable MPEG2 playback on even a lowly Pentium MMX).
In fact i remember being given a couple of those cards in that era since pretty much everyone could play DVDs without the dedicated hardware and no one could be bothered setting up the drivers for it.
The drives would operate in a fallback mode called PIO unless you installed specific drivers for the DVD drive. The symptoms you describe sound like this. 1.6Ghz was definitely enough for MPEG2 decoding.
If you were an OEM PC builder back in the 90s on margins so thin they could only be detected using an electron microscope, you'd be looking for the cheapest way to qualify for yet another sticker on your beige box. Naturally you'd gravitate towards solutions that minimised your part count. So we got sound cards with CD-ROM interfaces.
ATAPI = "ATA Packet Interface" https://en.wikipedia.org/wiki/ATA_Packet_Interface
ATA = "AT Attachment" https://en.wikipedia.org/wiki/Parallel_ATA
AT = "Advanced Technology" (possibly apocryphal or a retronym) https://en.wikipedia.org/wiki/IBM_Personal_Computer/AT
Where's my damn time machine?
There are so many ways to mess up. If we got time travel in the next ~40 years Google could probably catch casual time bandits by tracking early meme and emoticon usage.
I downloaded Slackware 2.1 on floppy disks and installed from that. By the next Slackware release my ATAPI CD-ROM was supported and I mail ordered a CD and everything worked fine.
ATAPI never had this problem as I understand it.