This Control Panel is the oldest accelerator. It is a patch for QuickDraw. There are many problems known with newer MacOS versions, especially MacOS 8. You should at least _not_ select "Fast invert". It accelerates the following MacPicassos: 320, 328, 516, 520, 540. It works on 68K and PowerPC Macs. It is still the only one accelerator for 68K Macs.