On Sun, 3 Nov 2024, Steve Lewis via cctalk wrote:
Non-descript 5.25 DS/DD (they don't format as 1.2M disk using a 1.2 5.25" drive, so I'm pretty sure they are actual 360KB disks). That said, I haven't really fully confirmed if it's a 1.2M drive. TEAC FD-55GFR 142-U, because I haven't actually come across any 1.2M formatted media.
Do they have hub reinforcing rings? If yes, then they are probably 360K If no, then they are probably 1.2M
