You have to do a marriage rites to get controller and MFM/RLL hard drive by doing the low level format utility after error list entered from the hard drive label, same thing with debug command (onboard bios called). Then next step is OS partitioning and high level format.

I'm glad to not worry about small 20-60MB range MFM/RLL they tend to be way too lightly built (esp seagate due to cantilevered spindle steel shaft made of soft metal. (had seen too many wobbling even platters were good due to rough handling). I preferred in hub motor design and high quality MFM/RLL or ESDI and more important rotary voice coil. I went with ATA hard drive (80MB Seagate ST-1102A) early on in the era of MFM/RLL days (late 1989 thru 1990's). Conner, NO THANKS. had high rate failure with them.

Cheers,