8" drive variations

8" drives do exist in both hard and soft sector formats, but soft-sector is overwhelmingly dominant (probably more than 97%). There is only one rotational speed (360RPM), and they all have 77 tracks. Some have one side, some have two sides. But after that, all hell breaks loose, because the density as well as both the number of sectors per track and the sector size can take on almost any values (and some formats have track 0 in single density with all other tracks in double density). Sector size can be any of 128, 256, 512 or 1024 bytes per sector, and the number of sectors is also not well standardized. Some early drives will not interface to a 765 well; later drives should not be a problem. However, the western digital chips had more flexibility and can do formats that the 765 cannot do.