I recently noticed there is a special utility that allows one to switch the graphic mode. The choices include Overlay, Direct3D, OpenGL, etc. What mode should I be using? How does one decide what mode is correct for them and their machine?

I can't be sure but I guess it won't change anything for this game, because it doesn't use 3D graphics.

Hi there,

This has nothing to do with ingame 3D graphics.
It is just the mode that DOSBox uses for displaying the game itself.

Best leave it to "surface", which should give the best results. If you have a slow machine,
then try switching to "overlay".