MS-DOS DEBUG Basics for Fixed-Format Files

The Microsoft MS-DOS DEBUG program provides a generally available tool for examining and analyzing files in a Microsoft environment. Files can be loaded and their internal data can be displayed (in hexadecimal) regardless of whether or not the data is encoded in a character format. You can also find some free graphical hex dump programs (e.g. "hexdit" from or "XVI32" from but DEBUG is usually already installed on Windows computers.

Unix/Linux/BSD systems come with an od command-line utility that can dump files in various formats, and various free GUI editors such as HexEdit (available on

The DOS DEBUG Dump/Display Format

Sample DOS DEBUG Dump Output:

1373:0100  46 FE 06 47 DB EB EF E8-DB F9 75 04 FE 06 A3 D8  F..G......u.....
1373:0110  3C 3F 75 05 80 0E A7 D8-02 3C 2A 75 05 80 0E A7  <?u......<*u....
1373:0120  D8 02 3A 06 94 D2 75 C9-4E 32 C0 86 04 46 3C 0D  ..:...u.N2...F<.
1373:0130  75 02 88 04 89 36 6B D7-89 0E 69 D7 C3 BE 48 DB  u....6k...i...H.
1373:0140  8B 4C 05 8B 74 09 E8 08-00 03 F1 E8 03 00 3C 0D  .L..t.........<.

Running Debug: Basic Commands

A File Dump Example using DEBUG