[hermanhermitage]

The native disk format was actually broken into sectors, see:

http://amigadev.elowar.com/read/ADCD_2.1/Devices_Manual_guid...

It read full tracks at a time, but you can see from the doc there were 11/22 sectors with no inter sector gaps, but there are separate sectors of 512 bytes which are addressed in the file system structures.

[pierrebai]

That's just a clash of nomenclature between the logical and physical layout. It had logical sectors, but on disk, it was written as one contiguous sector.

[puzzle]

Yes, it read the whole track, starting from wherever the head was, then the floppy device handler figured where each logical block was, based on the magic sync word $4489 (which is not supposed to be output by the default MFM encoding) and track/sector IDs embedded in the track's bitstream.