Anyone else besides me remember this?  It was an add on for Champion Edition and was illegal.  It was also known as Accelerator, Accelerator II, and Quicken.  It was the reason Hyper Fighting was created by Capcom.   It had features like Midair moves, arcing fireballs, no charge time, many fireballs thrown at one, and character changing in middle of the round when the start button is pushed (it scrolled through the character and you would just play as the one you want when their appear).

Here are the Blackbelt Dipswitch settings thanks to Console Horizon.