Since we want to recover the data, of course, we have to mention the storage principle of the data. At the same time, we also need to introduce the data deletion and formatting of hard disk. ...

File reading

The operating system reads file information (including file name, suffix, file size, modification date and cluster number of the first cluster stored in the data area) from the directory area. Suppose the first cluster number is 0023.

The operating system reads the corresponding data from the 0023 cluster, and then finds the 0023 unit of FAT. If the content is the end of file flag (FF), it means the end of the file; Otherwise, the content saves the cluster number of the next data cluster, and so on, until it meets the end of file flag.

Compilation of documents

When we want to save a file, the operating system first finds an empty space in the DIR area to write the file name, size, creation time and other corresponding information, then finds an empty space in the data area to save the file and writes the first cluster in the data area to the DIR area. Other actions are similar to the above reading actions.

File deletion

After reading and writing the previous file, you may not have the confidence to continue reading, but rest assured, the file deletion of Win9x is very simple, as simple as making a little change in the directory area-changing the first character of the file in the directory area to E5 means that the file will be deleted.