3.5" floppy jumpers

I have 3 3.5" floppy drives with configuration jumpers (and 5 times as many without :-) ). Ons is a Chinon FZ-357, and has jumpers for: MD, RDY, MM, DC, and TTL/C-MOS. Another is a TEAC FD-235HF and has jumpers for: H HO, OP, LHI, HHI, and a position (but no header pins) for FG. The last is a Sony MPF520-1 which has 2 rows of 3 pins... and I have no idea what they are for. I understand some abbreviations... RDY (ready), DC (disk change), but not MD, MM, TTL/C-MOS (assuming this is for interface logic levels?), and the TEAC ones I don't know at all. The Sony one is a mystery, and a google search hasn't turned anything up... don't know if the headers are for selecting D0-D3 only... or more than that. Can someone fill me in/point me to web pages on these 'magic' jumpers for these drives ? Thanks, -- Curt