good evening and many thanks for the tips...I taped up the permanent hole on the floppy and ran the format from the DOS window...the disc changed format to FAT and told me that it wasn't supported??!!!...When I tried to xfer a MIDI file from the pc I got a message (again) that the disc needed to be formatted???!!!!....If I weren't already bald, I'd pull my hair out.....I'll connect the old 500 to the 850 with MIDI IN and MIDI OUT and change the settings on the 850 to ADD instead of REPLACE and see if I can get a better handle on this......what gets me is that the discs were all reading just fine befor "something" happened.....ACCKKK technology!!