On 3/30/23 10:48, Fred Cisin via cctalk wrote: > The drives in many IBM PS/2 machines don't seem to have a media sensor, > so they can't tell the difference between "720K" and "1.4M" disks. > "720K" is about 600 Oersted, and "1.4M" is about 750 Oersted, so they > are close enough that sometimes one can get away with using the wrong one.
Those PS/2 drives often have peculiar IBM-specific interfaces. For example, some are 40 pin instead of 34. Or power is shared on the same cable as signals, etc. You're not likely to consider them. > There once existed single sided drives. Such as the original Shugart > SA300 They were used in early Gavilans, but were replaceable with double > sided, especially the SA350, which could use the Gavilan's custom SA300 > bezel, > > Epson Geneva PX8 was 40 cylinders, intead of 80, with 67.5tpi, instead > of the usual 135tpi.> > The original Sony FULL height drives were at 600RPM, and had a different > interface. > > The Tandy Portable Disk Drive, for the model 100, was weird and a half. But none of those are high-density drives. I'll add one of the issues may be drive-select setting for non-PC devices. It's easy enough to get around, however. --Chuck
