What is hard format and soft format?

Answer 1

1. hard sector formatting - sectors are separated and identified by physical notches or holes in the media that are detected optically, a counter register counts the pulses from the sensor and the number in this hardware register identifies the sector being read or written.
2. soft sector formatting - sectors are separated and identified by coded address fields recorded on the media during formatting, as these address fields are created by the formatting software the sectors can be placed in any order (not just sequential as hard sector formatting does) around the tracks or skewed from track to track that might improve access time on a given system.

Both systems usually have a single physical notch or hole in the media used to identify the beginning of track. On a hard sector formatting system the pulse from this resets the counter register to zero. On a soft sector formatting system this pulse may or may not be used, depending on system requirements (e.g. on floppy disks when the drive could accept either single or double sided disks this hole was in different positions and was detected by a different sensor for each type of disk).