1.2M HD / 300kbps / single-density

Dave, that's very strange. I just went and tried it on one of my "regular" systems, a box with an Intel TC430HX mobo in it. The controller on this board is a National PC87306B (serial/parallel, clock, floppy, IrDA and keyboard) that does just fine with FM. I repeated on another "regular" box with an Intel PD440FX board (uses the NS PD87307) with the same results. In both cases, the drive was a Teac FD55GFR running at 360 RPM. 'Matter of fact, I have to be very careful with the first machine-- it's got a Toshiba 1.44M 3.5" on it that will automatically change spindle speed if a 1.3MB 3.5" diskette is inserted without giving any external indication. In both machines, I coiuld format, write and read 48 and 96 tpi SD formats in the 55GFR. (Those intel 400-series mobos are great because they use the NS Super I/O chip--it's 8473-compatible, which means it'll also handle writing 128-byte MFM sectors, unlike its NEC-based relatives.) I wonder what's up with your setup? Cheers, Chuck