The raw floppy driver doesn't check that the requests are physically possible. With 20b (10k) being the (currently) largest possible block, all IO requests on a 360k floppy will fail (2 tracks = 1 cylinder = 2x9 sectors = 18 blocks), the driver reporting an unknown error. Using the track size as block size in such cases will work and is the preferable workaround.
This problem will occur with any block size if the request spans a cylinder boundary. e.g. dd if=/dev/rdf0 skip=17b bs=2b will fail on a 360k floppy.
Mellvik
commented
5 months ago
The raw floppy driver doesn't check that the requests are physically possible. With 20b (10k) being the (currently) largest possible block, all IO requests on a 360k floppy will fail (2 tracks = 1 cylinder = 2x9 sectors = 18 blocks), the driver reporting an
unknown error. Using the track size as block size in such cases will work and is the preferable workaround.This problem will occur with any block size if the request spans a cylinder boundary. e.g.
dd if=/dev/rdf0 skip=17b bs=2bwill fail on a 360k floppy.