I wrote a simple tool for the Apple DOS Compatible card for PowerMacintosh 6100. It allows you to enable/disable Turbo mode and adjust the de-turbo speed and disable cache to run software that doesn't run on a 486.
I tested it with Monkey Island EGA, Loom EGA and LucasFilm Night Shift, none of which run on a 486 66Mhz while using Adlib sound. All are working with this tool.
It should work on any 486 board with a CHIPS 84032 and 84035 chipset. Tested in MAME/MESS with AMI BIOS clone 486/66 Mhz and on a genuine Apple DOS Compatible card.
Source and binary are on Bitbucket.
