You might look into trying either QEMU or Bochs. You can install FreeDOS on a virtual disk, and run your app under it within either emulator. I don’t know if either of these will cause visual problems for you, but QEMU seems to have a pretty neutral interface (I use it in my Operating Systems and Systems Programming classes, and haven’t heard any complaints from students about that aspect, but anecdata isn’t proof).
EDIT: typos do vex me greatly!
I miss ports.
TV stations are still very common!
Watch any of thousands live here:
I have that same pile, but they’re all bulged out from the swollen batteries
Imagine if the batteries were removable 
Yeah but who really does that.
The bottom two at least, I’m fairly sure I changed batteries on, I can’t remember when they started soldering memory exactly, 2014 maybe? I updated ram on occasion.
Even the current ones you should be able to change the batteries in, if you’re up for it.
Re: top photo
I thought it was funny that from the beginning laptops always had covers for the ports, and then all of a sudden they didn’t.
I remember at some evolutionary stage cleaning them out with a paper clip.
