Disk editor

A disk editor is a computer program that allows its user to read, edit, and write raw data (at character or hexadecimal, byte-levels) on disk drives (e.g., hard disks, USB flash disks or removable media such as a floppy disks); as such, they are sometimes called sector editors, since the read/write routines built into the electronics of most disk drives require to read/write data in chunks of sectors (usually 512 bytes). Many disk editors can also be used to edit the contents of a running computer's memory or a disk image.

Unlike hex editors, which are used to edit files, a disk editor allows access to the underlying disk structures, such as the MBR, volume boot records, 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. Sometimes these structures are edited in order to provide examples for teaching data recovery and forensics, or in an attempt to hide data to achieve privacy or hide data from casual examiners. However, modifying such data structures gives only a weak level of protection and data encryption is the preferred method to achieve privacy.

Some disk editors include special functions which enable more comfortable ways to edit and fix file systems or other disk specific data structures. Furthermore some include simple file browsers that can present the disk contents for partially corrupted file systems or file systems unknown to the operating system. These features can be used for example for file recovery.

History

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 (re)loaded 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). Having the disk editor on cartridge also helped the user avoid editing/damaging the disk editor application disk by mistake.

All disk editors strive to be better than DEBUG contained in all DOS versions. DEBUG can load, edit, and write one or more sectors from a floppy or hard disk based on the BIOS. This permits simple disk editing tasks such as saving and restoring the master boot record and other critical sectors, or even changing the active (= boot) partition in the MBR. In an NTVDM under Windows NT DEBUG cannot access the physical drive with the MBR of the operating system and is in essence useless as disk editor for the system drive. The Resource Kit and the support tools for some Windows NT versions contain DSKPROBE^[1] as a very simple disk editor supporting the use and modification of the partition table in the MBR and related tasks.

List of some disk editors (or products containing them)

Windows

Free Software

• HxD - fast and intuitive hex editor (including disk editor and RAM editor) for Win9x/NT and up.
• wxHexEditor - designed for huge files/disks. Tested up to 1 PetaByte drives. It's Open source and Cross-platform.
• Roadkil's Sector Editor - A lightweight sector editor which can also save a specified number of sectors to a file (all functions tested good under Windows XP Pro).
• ICY Hexplorer - Hexplorer doesn't format file content, but it displays it as it is, that is as binary data, allowing you to edit it hexadecimally or like text editor does, so it gives you low level access to each kind of file, providing many tools to operate on data. (this description may need cleanup)
• iBored - cross-platform block oriented disk and file editor with templates system and remote network disk access. Knows several common disk structures such as MBR, GUID partitions, Apple Partition Maps, FAT16, FAT32, UDF, ISO 9660, and a bit of HFS, ext2 and NTFS.

Proprietary Software

• HHD Software Hex Editor Neo - Fast and reliable hex editor (including disk editor, process editor and RAM editor) for Windows 2000 and up.
• Hexprobe Hex Editor - A professional hex editor for Microsoft Windows capable of editing and searching in hard-disk and logical-drives.
• WinHex - forensic, file recovery, disk cloning, full disk, image and memory editor (extra features when editing FAT, NTFS, CDFS and Linux file systems); runs under Windows NT and higher (older versions can be used under Win9x).
• T-Software Technologies System Console - Multifunctional system software. Allows to process any part of hard drive, floppy drive, CD/DVD etc, including hidden partitions and unpartitioned space; runs under Windows NT and higher.
• Runtime Software Disk Explorer FAT/NTFS - tool that allows for copying and pasting at the byte-level in addition to full sectors. Companion to the GetDataBack and Drive Image XML tools.
• R-Tools R-Studio - forensic tool that competes with WinHex. The suite has the editor in addition to a powerful selection of tools. There are multiple 'levels' of features depending on price.
• DMDE - multifunctional disk editor and data recovery software for FAT, NTFS. Disk editor is freeware for non-commercial use.

Linux

• wxHexEditor - designed for huge files/disks. Tested up to 1 PetaByte drives. It's Open source and Cross-platform.
• hexedit shows a file both in ASCII and in hexadecimal. The file can be a block device file as it reads portions of it on demand. You can modify the file, search through it and more.
• shed (simple hex editor)
• Linux disk editor (for ext2 file system).
• debugfs (debugger and editor for ext2)
• iBored - (Freeware) cross-platform block oriented disk and file editor with templates system and remote network disk access. Knows several common disk structures such as MBR, GUID partitions, Apple Partition Maps, FAT16, FAT32, UDF, ISO 9660, and a bit of HFS, ext2 and NTFS.

Mac OS X

• iBored - (Freeware) cross-platform block oriented disk and file editor with templates system and remote network disk access. Knows several common disk structures such as MBR, GUID partitions, Apple Partition Maps, FAT16, FAT32, UDF, ISO 9660, and a bit of HFS, ext2 and NTFS.
• wxHexEditor - designed for huge files/disks. Tested up to 1 PetaByte drives. It's Open source and Cross-platform.

MS-DOS

• Norton Utilities DISKEDIT (for FAT under DOS); still packaged with many commercial Norton products for Windows.
• Diskman disk editor Old but powerful disk / sector editor for DOS. Freeware.
• WDe disk editor Very simple but well designed; ASM source code included.

Atari ST

• Diskus by Uwe Seimet is a powerful graphical Disk Editor for Atari ST (FAT filesystem)

Commodore 64

• Epyx FastLoad for the Commodore 64 computer and 1541 disk drive
• The Final Cartridge (C64/1541)
• Action Replay (C64/1541)
• Locksmith II (disk) for the Commodore 64 computer and 1541 disk drive

Apple II

• Copy II Plus (disk) originally for the Apple II computer and Disk II or compatible 5.25-inch drives using the Apple DOS 3.3 and 3.2 filesystems. The latest versions added support for 3.5-inch drives and ProDOS formatted 5.25-inch disks. With ProDOS support, came support for block devices recognizable by ProDOS, such as the ROM or RAM drives on the Apple IIGS.

See also

• dd (Unix) allows read and write access on disks and other devices
• Hex editor
• Partition editor

References

1. ^ "Dskprobe.exe: DiskProbe". Microsoft Technet. 2003. http://technet.microsoft.com/en-us/library/cc736327(v=ws.10).aspx. Retrieved 2011-07-05.