So after some trial and error, the issue appears to be related to PDCurses 3.4 and an incompatibility with the fall creators update from Microsoft. Compiling with PDCurses 3.6 appears to resolve the issue.

Since installing the fall creator's update for Windows 10, I've been experiencing issues with using DosBox to debug / step through some simple DOS programs. For the last release (0.74), the debug screen comes up blank. I checked out the latest version from SVN, compiled with --enable-debug using …