It depends on what type of hardware. On the right console you could do this in real time with nothing but a jammed opening mechanism. I've personally swapped disks on a launch PSX just by learning the right timing and made it work 9/10 times. By 2000 I also knew of multiple places to just get hard mods, but honestly, Bleem came out in 99, so... that would have been my go-to. And now... well, now you can get a MiSTer to run those games if what you want is OG I/O.

I'm gonna say if you're a "OG hardware" kinda person, and I'm one, so I should know, you're also a OG software kind of person. I'll play a real PSX game on a real PSX for shits and giggles, but if I'm gonna burn a CD I have better ways to get that game to run if I am using bootlegs on any part of that chain. Also, if you're a OG hardware kinda person, you may be in the same boat I am and have such restricted shelf space that your default PSX vessel is a PS2 because if you can consolidate two consoles into one that's way more useful than a way to run copied CDs, although that may be a me thing.