I have a MPI (CDC) 5.25 full height 2sided drive and some questions. Part number is 77711800 is this 35, 40 or "other" cylinders? is it 48tpi, 96 or maybe 100 tpi? It gets cranky from tracks 9-14 inward (even a Format) and it makes me wonder what it is or is it just flakey? Appearances suggest flakey but I'm making sure it's not an oddball MPI 100tpi. FYI: it's a NS* Advantage and it runs fine off a generic HH5.25/48tpi floppy. Anyone have a NS* CP/M OS manual for it. It has CP/M and it's apparently a NS* version for the Advantage and slightly strange compared to others I've seen? Allison