It says put an 8" ON a PC, not IN it.
If you use two side by side drives horizontally,
then it is a lot more stable to put the PC on the 8"
You would have
trouble putting them IN a PC, as most 8" drives I know about,
use +24VDC, which is not found in a PC.
I also have/had a horrible one, originating from a Philips mini (PTS6000)
which used 115VAC for one of the motors
Nico