On 2/22/22 16:12, js--- via cctalk wrote: > As Chuck noted, I'd think you'd want to use 360K media -- not DSHD > diskettes... and ensure that the 1.2MB drive is slowing down to 300RPM > with a data rate of 250KHZ. > > These features will depend on the 1.2MB drive you have, as well as your > FDC and imaging software.
Use low-density media--the high-density stuff really requires higher write currents (media is formulated for higher magnetic coercivity) to work to spec. Any PC that supports 1.2M 5.25" high-density media has a controller that can vary the clock rate between 250, 300 and 500 Kbit/sec. Clearly, if you're using a garden-variety "1.2M" drive, you'd want to use the 300K data rate, as those drives *generally* spin the disk at 360 RPM. (sort of a mountain-Mohammed issue. If you can't slow down the spindle speed, boost the data rate). There are several PC (MS-DOS) utilities that can handle this. You pretty much need the ones that do low-level controller access, as most PC software assumes that low-density disks will double-step to get the standard 48 tpi track spacing). If you're bamboozled by any of this, drop me a line and I'll shoot you a simple MSDOS utility that will write RX-50 disk formats on a standard PC. --Chuck
