Oh yes, I remember the Turbo button very well and the drama around it. I never had those kind of older PCs as I only really started from 2004 with broadband internet for me, but my only experience with the Turbo button was in elementary school as a kid.
The elementary school had a PC-room that was suppose to be used for computer class but several PCs had Duke Nukem 3D and many other games installed, Commander Ken, Dangerous Dave and I don't remember but I wish I could go back into that room today for a blast to the past, and yes internet worked too. The-geek-class-pc-caretaker-teacher would show us mIRC (but I didn't use, or had any idea how to use it) we usually had to do only school stuff like Word documents, Excell, etc but they would let us play games on fridays, let's rock! Duke Nukem 3D LAN parties ... and even the teacher would play with us on the Admin-Teacher-Only-Computer, and I think like only 4 student PCs had DN3D (were good enough for) so you can imagine the circus of my-turn your-turn and there was a lot of keyboard splitting/sharing (or how is that called) of one student being responible for walking and other for shooting.
The PCs were quite various and only 2 of them were really good, 4 of them okay, another 4 medium and 2 were really bad and slow like crap, many of the medium and weaker-older ones would had a DIGIT screen that would show either "20", "40", "60" or "80" (only on the 2 best ones), I think if you pressed Turbo then it would go from 40 to 60, 60 to 80, but there was a catch to it and I don't remember what was the downside of Turbo at the time (I think I still don't, I think i saw it explained on LGR but forgot again), but the 2 bad ones were at 20 were super slow and had no 3D games so what do you guys think what happened, it was an absolute circus across the whole school facility, a mad dash after the end of the class before the computer class, running full speed to be the first one or else, because you had to be the first in the line to get to the best two PCs as the teacher opens the door to the PC room, if you're not in the top 10, you'll get the crappy PC or worse you wouldn't get any PC as there were total of ~20 students in the class and you had to share, 2 students per-PC could sit the way room was structured, I don't remember exactly how often would two switch seats and be the primary user of the PC, but I think it was actually better than being on the bad PCs because once you had your seat there was no changing of computers for the remainder of the class, I'm not sure if it was a rule but I think the teachers were okay with this always being determined at random by the crazy stampede that would ensue when teacher opened the door, it was fair I guess.