soft sectored

"The drives are soft sectored, single or double sided, with 40 tracks per side.

Most soft sectored and all hard sectored drives would have also required an extra cut-out for the index hole - a harder modification.

Because of the similarity in magnetic characteristics between some disk types, it was possible to use an incorrectly certified disk in a soft sectored drive.

Later soft sectored disks had only one index hole, and sector position was determined by the disk controller or low level software from patterns marking the start of a sector.

Floppies: 8 inch hard and soft sectored: These I cannot read, however, most of mine were archived into 3.5 inch 1.44M floppies (FAT).