SCSI2SD Imaging
So this is how SCSI2SD deals with devices set to use 256-byte sectors, as required by ADFS. It puts the sector data in the first half of its own internal organisation of 512-byte sectors, and fills out the second half with &FF bytes. This is a significant difference to how IDE-based interfaces deal with the same issue - they write a dummy byte after every good byte to make up the 512 bytes of a sector, whereas SCSI2SD writes a dummy sector after every good sector.