The main competitor of the µPD765 FDC chip on the market was the WD179x FDC chip family. Its main differences are:
* the 765 has 4 status registers , while the 179x only has one.* the 765 has 3 scan commands , while the 179x has none.
* the 765 only does standard track formats (preamble, marks and data fields), while the 179x will write anything you tell it in the write track (formatting a track) mode.