Eximo :
I had so many chassis with a turbo button, but it was only functional on my old 133Mhz SX, we used it for some non-updated games without speed limiters.
Um, 133 MHz and SX don't go together, in my recollection. By the time anything ran that fast, the SX nomenclature was in the dustbin. Perhaps you mean 33 MHz SX? If not, what CPU did it have?