JSmith5528: Many thanks to you, philscomputerlab. Now back to enjoying the Doom!
I find it works even better with a source port. Higher screen resolution so sprites keep their detail at longer range which makes the game look so much sharper (plus you can optionally enable various post-processing effects if you wish, and some ports allow you to swap the sprites for 3D models like Quake, but I prefer to keep the sprites myself).
Chocolate Doom keeps the game vanilla, as it was created, so all the bugs that were in the original game are still present in Chocolate Doom, but the advantage is a native Windows engine instead of running it via the DOSBox DOS emulator, so better performance.
ZDoom is a common one and spawned some offshoot ports, too. I use the GL offshoot of it, GZDoom. Modern mouselook and WASD, plus with vertical aiming instead of relying on the game to auto-aim along the vertical.
Zandronum is designed for multiplayer, should you want that.
There are others, too.