Board Thread:M.U.G.E.N Help/@comment-32384321-20190515034131/@comment-3495717-20190515182734

If you're using 1.0 as you say, there should already be a few empty slots by default, though not many; also included with 1.0 is a 'big' motif that increases the slots up to 60 or something like that, complete with instructions on how to install it. Of course if you want anything bigger than that, you'll have to edit the current motif/screenpack's system.def file to increase the number of rows/columns (but then you have to reposition everything) or download a new screenpack.