What is backward MMFM? Hmmm...Is this the Lanier that uses hard-sector 8" floppies, 256-byte sectors backward MMFM? I deciphered a couple of those years back. Sorry, don't have any program disks, just data.
MMFM is a (1,4) RLL encoding- I guess it requires a more precise sensor than MFM, a (1,3) RLL encoding, due to the higher number of sequential 0 bits (lack of transition).