That brings back memories, and now I'm trying to use DOSBox to listen to the RealSound PC Squeaker intro music for Echelon (1988) in eXoDOS ... but I only get silence. Maybe DOSBox doesn't simulate the physical properties of the speaker, or the RS timing hacks, well enough for their PWM to work.
Looks like someone made it work: https://www.youtube.com/watch?v=7xHub6wRkbQ
Any tips?