formatting and checking floppy disks for bad sectors

On Sat, 30 Jul 2016, Fred Cisin wrote: There used to be a `fdformat' utility available providing fancy stuff for DOS users like sector physical and logical shifting, interleaving, unusual geometries, etc. You could use physical shifting (track lead and inter-sector gap rearrangement) to avoid bad spots in some cases altogether, and logical shifting (out of order sector ID assignment) to improve data transfer performance -- typically ~twice compared to results obtained with the regular `format' utility shipped with DOS. Some other features were available I don't remember offhand anymore; basically you had much control over the NEC ?PD765 FDC chip itself with this tool's command line options. Back in 1990s the software package used to be carried by the usual FTP sites with DOS software, so I guess it still has to be available online somewhere. I highly recommend it if you're still into the floppy business and don't use Linux. The plain `format' command supplied with DOS gives you little control really and produces poor performance floppies. HTH, Maciej