A patch utility that fixes the speed issues the DOS games Mega Man and Mega Man 3 have when run on faster computers.
https://www.patreon.com/posts/mega-man-dos-and-28839430
Simply place MMPATCH.EXE in the game folder next to MM.EXE and run it to generate the fixed executable (MM1.EXE or MM3.EXE).
This utility must be run in a DOS environment, like the game it patches.