I have a manual for the line of computers Magnavox (Philips) produced. There are a couple of programs it mentions. I have the Philips 5107-200-35451 386SX 16.
There isnt a turbo button header on the motherboard. The only way to switch the turbo is going to in the bios each time.
The manual calls out a SPEED.COM program that should allow for at runtime switching of the cpu speed.

Likely a long shot but does anyone have this program (and maybe the others)?