I use a strobe disk glued to a fridge magnet that I stick on the spindle motor of 5 1/4" drives to confirm the speed; the trouble is that it's becoming difficult these days to find lamps that emit light at 60 Hz. ;-)
On Sun, Nov 3, 2024 at 10:21 PM Chuck Guzis via cctalk < cctalk@classiccmp.org> wrote: > On 11/3/24 18:44, Fred Cisin via cctalk wrote: > > 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. > >> I've wondered if maybe one of the heads on the D: drive the Sharp > >> PC-5000's > >> dual disk drive might have some kind of issue (either the REad or Write > >> head, not sure which) - just since it seemed more likely to end up with > >> some bad sectors marked when using FORMAT.COM (whereas on other > systems, > >> the same disk would format fine with no bad sectors). > > > > Teac FD-55GFR is a 1.2M drive that can also be used as a 720K 5.25" > drive. > > (FD-55G is 1.2M; FD-55F is 720K) > > Just be sure to set the drive jumpers so that the spindle speed is 300 > RPM, not 360, which is the usual default for PC drives. > > --Chuck > >
