What Mike said. IIRC from 30+ years ago, the TRS-80 Model III could read and write both FM and MFM. The issue with drives was the difference between 40 track and 80 track formatting. Because an 80 track head writes a narrower track, using it to update a disk written by a 40 track drive was likely to make the disk no longer readable on a 40 track drive. I remember using a cassette tape bulk erase to completely erase 40 track disks before reformatting them as 40 tracks with an 80 track drive, writing only every other physical track on the drive. This did work.
I suspect the controller in an Amiga could handle this, provided you had a suitable drive connected, and suitable software to do the job. I'm sure there are Catweasel boards still around, but you probably can't buy a new one these days. Alas, I have a working Amiga 3000 but no Catweasel. (Just checked, there are Catweasel boards listed for sale on eBay, at least.) Yeah, I think Catweasel could do it, given enough time to fiddle with it (and enough 5.25 inch floppy diskettes, another rare item these days.) --Gary
