Doom not properly working on 486SX-66

[Chiphead]

So Ive been playing the original doom on an old school dos 5.0 pc and there are ton of issues preventing me from playing it the way it was meant to be played. Firstly, in normal speed mode after installation the game feels a bit choppy and sluggish almost like playing it on 386 pc or a pc which is less powerful than the one I'm using which should do the job optimally in normal speed, also the intro screen moves slightly too fast, sometimes during the selection screen, direction sometimes needs to be repeated for the option to register, but it is somewhat playable and a bit decent in general, but not as optimal as it should be.

I'm using a 486DX2-66, 8MB RAM, vlb CL-GD5424 with 1mb, Sound Blaster 16. 256 K of cache, Dos 5.0

In turbo mode what remains is a minor speed up in the intro screen, and the need to sometimes repeat the selection in the selection screens but I do get sort of a perfect speed in the game, solider shoots automatically which is odd at the beginning, but a few mins in the game, the game slowly crashes or more often the current screen gets suddenly morphs into a strange horizontal line bar within a black background where it becomes practically unplayable, this happens every time.

I've also noticed the same bizzare horizontal line thing with many games when I originally got the pc with this setup. I've had to take out disable univbe setting to make them run normally, which they have. However enable and disabling univbe for doom had no effect.

Also it is worth mentioning that the game was 1.22 release from early 1994 and installed from the original floppy disks with the exception from one image on the third disk which wasn't reading. The third floppy was copied to a floppy from this source which is pretty much identical to the box and disks I have: https://archive.org/details/doom1.21

I don't have any more spare floppies so I can't copy any more files or play it via dosbox. I'm into real deal here as much as possible on old school machines as well.

It's likely the files and installation is not the problem and it is a matter of setup tweaking.

In the wetransfer file below there are more pics related to setup info and examples of what I'm talking about.

Can anyone help out? So I can play this game the way it was supposed to be played. I already have the needed specs to run it perfectly. The setting needs tweaking or the problem (game version or hardware part) needs to be identified if this isn't the case which seems unlikely.

https://we.tl/t-s6FtANrADH

https://we.tl/t-Wfs06gPP5M

[MrFlibble]

I think you'll get more competent advice if you ask around VOGONS:
https://www.vogons.org/viewforum.php?f=7

This is exactly their forum section for running real DOS stuff.