Sometimes you also needed to switch L1 and/or L2 cache off to get correct speed in addition to pressing turbo button.

If you were unlucky, underclocking was the only option to get the speed just right. Not fun in the era when clock speed was set with mainboard jumpers...

Of course there were also TSR [0] utilities to slow down old games.

I remember twiddling with all that to get some early XT era games working properly. Computers were getting faster so quickly that you'd literally see a new faster model for sale in as little as 1-2 months later. Slowing down things just right amount was an art form in the mid to late nineties.

[0]: TSR: https://en.wikipedia.org/wiki/Terminate_and_stay_resident_pr...