From my past experience I could recommend some tools...
for example - DosBox
DOSBox is emulator software that emulates an IBM PC compatible computer running MS-DOS. It is intended especially for use with old PC games. DOSBox is free software.
DOSBox can be used to run old MS-DOS software, especially games, that would otherwise not work on modern computers.
http://www.dosbox.com/
dosbox has a very powerfull, softice like debugger inside
if you want 16bit debugger, I've some in my can