Disk editor

Unlike hex editors, which are used to edit files, a disk editor allows access to the underlying disk structures, such as the master boot record (MBR) or GUID Partition Table (GPT), file system, and directories.

Programmers can use disk editors to understand these structures and test whether their implementation (e.g. of a file system) works correctly.

Disk editors for home computers of the 1980s were often included as part of utility software packages on floppies or cartridges.

The latter had the advantage of being instantly available at power-on and after resets, instead of having to be loaded or reloaded on the same disk drive that later would hold the floppy to be edited (the majority of home computer users possessed only one floppy disk drive at that time).

DEBUG could load, edit, and write one or more sectors from a floppy or hard disk based on the BIOS.