Other than FM, MFM, RLL and some newer ones what other
magnetic
disk encoding
schemes are there?
By "RLL" I assume you mean RLL 2,7 (at least 2 transitions in every 7 bit
times) - the one that gave about 50% greater capacity than MFM on "the same"
drives.
"MFM" is technically RLL 1,2 (ISTR)
There was also a controller whose name escapes me that used RLL 3,9 to get
90% greater capacity.
Andy