If you program under Windows 3.1x or Win95/98 (but not WinNT), 386SWAT presents itself to Windows as a very low-level debugger. Essentially, 386SWAT is provided the same level of access as the remote debugger WDEB386 shipped with Windows. WDEB386 requires that you run it from a separate system with a COM cable running between the two systems. In contrast, 386SWAT runs on the same system being debugged, however it does require that you have a monochrome adapter and monitor installed in the system.
For more details on this topic, see the file WINKDBG.DOC.