Debug, CDBA, WDW and debxxf

A. Debug

Debug is an extended MS Debug clone. There are two binaries available: the small and simple DEBUG.COM, which can debug DOS 16-bit real-mode applications only and DEBUGX.COM, which additionally can debug protected-mode DPMI applications, both 16-bit and 32-bit.

Read Debug's Readme.txt for more details. Also included is a DEBUG tutorial (PDF version).

Some screenshots of a DEBUG session

Debug v1.25 08/08/2011 binary + source changelog

List of all versions available for download

Note that there are newer versions of this program available at, with additions written by Vernon Brooks.

B. CDBA (Win32 and Win64)

CDBA is a CDB-like debugger - with a commandline UI - written in assembly (Masm-style). This debugger uses the MS Debug Engine. There is a Win64 version, CDBA64, and a Win32 version, CDBA ( CDBA can debug Win32 applications and DOS applications running in NTVDM). All debuggers allow debugging on both assembly and source code level. CDBA is Public Domain.

CDBA v0.80 08/07/2012 binary + source


This is a modified Open Watcom Windows GUI debugger. Unlike the original, this version allows to debug not only Win32, but also DOS and Win16 applications locally, without the need for a remote connection or using the VDM trap file.

WDW v1.9 01/2013 binary

The source is also available, but requires some manual work until it will compile without errors.

D. debxxf

debxxf is the name of a DPMI debugger for DOS and Win16 applications. It has more features than the simple DEBUG, but OTOH it won't run with simple DPMI hosts like cwsdpmi and it needs more memory.

There are 3 incarnations of debxxf: The DOS versions of the debugger have the following features: There are also some things which you might not regard as a feature:: Read debxxf's changelog.

Some screenshots of a debxxf session
v2.9.6 01/11/2008 debxxf (DOS) deb16fw (Win16)
v2.9.5 12/06/2007 debxxf (DOS) deb16fw (Win16)