An update to smkdan's age-old hack demonstrating the capabilities of an addon device for the SNES that eventually became the MSU1, but used to be a completely different beast altogether up until the latter was conceived.
For more information, please check readme.txt
N.B. To get this to work on higan v096+ out of the box (i.e., with the "Ignore Manifests" option checked), please consult the appropriate section of byuu's message board.
Have fun! :-)