1.2M HD / 300kbps / single-density

On 19 Mar 2007 at 5:35, Dave Dunfield wrote: No, but it's not a practice I've followed much. Many, if not most, of the FM-encoded 5.25" (exclusive of the 100 tpi format) formats use 48 tpi diskettes, so we've always recommended a 48 tpi drive to do the work. And I don't think we have a single system here with your SMC controller, although I think I still may have the datasheet somewhere here. It might have happened to us at some point with a customer, but we'd have assumed that his was one of the many controllers that don't handle FM at all, so our advice would have been the same--find another mahine to try. The problem may have been masked entirely by this. When doing your testing, remember to separate the non-FM capable controllers from the FM-capable-but-not-at 300K ones. Don Maslin and I did start doing a fairly exhaustive survey of LSI single-function diskette controllers to see what could handle FM and 128-byte sectored MFM, but that was long ago, and we didn't include the very new multi-I/O chips. Maybe it's time for a new census, although I wonder--many systems made since about 1995 won't support more than a single floppy anyway-- and I suspect that floppyless desktop PCs aren't that far off from becoming the rule (many are still shipped with a 34-pin header on the mobo just in case, but that won't stay around, I suspect). Cheers, Chuck