Other Types Of Error Sectors:

In addition to the "bad sector" described there are several other types of sectors which will cause the 810 to return an error to the application program. They are known as the deleted data mark sector, CRC error sector, and double sectors. There are three advantages to using these other types of non-standard sectors. They are:

1. They do not cause the familiar and much hated grinding noise from the 810.
   
2. They are identified faster than a bad sector. This allows copyguarded software to boot-up faster without the crunch, crunch of a bad sector.
   
3. Most importantly, they can't be reproduced by slowing the drive down. Without hardware modifications, there is no way to generate these sectors.

There are also several associated software techniques used with these types of sectors. These include sector timing relationships, and double sector verification.