I think I've found the cause of the problem. It seems to the be DOS mouse driver, or the mouse I'm using. Because if I don't use the mouse to play, I'm not experiencing the issue.

I've tried two different mice so far.
Mouse 1: Microsoft Compact Optical Mouse 500 - This mouse makes the keys "stick" some times.
Mouse 2: Logitech G403 - Using this mouse I loose the keyboard and mouse after a few seconds, which leaves me unable to do anything but reset the computer.

So any advice to what mouse driver to use, which can handle modern optical mice. Or an easily available and affordable mouse which will work well in DOS?

EDIT: I went out an got a cheapo optical USB mouse, with a PS/2 adapter and the problem still remains. The mouse driver is CuteMouse v1.9.1 alpha 1 (downloaded from PhillsComputerLab)
I'm going to try updating the driver and play around with some settings.

EDIT2: CuteMouse v2.1 beta 4 has the same issues and they seem to occur more frequently.

EDIT3: I'm at the end of my rope here. Not sure what to do anymore. I've tried yet a different mouse driver, one from Logitech. Iv'e tried two different keyboards. I've tried using the PS/2 adapter on the keyboard instead of the mouse. (Yes, I used the PS/2 keyboard port.)

The issue still remains. If I use mouse and keyboard at the same time to play, the games (DOOM and Duke 3D) will randomly walk in one direction by it self, even if I'm not pressing any keys. The only way to stop the walking is to press the key that corresponds with the direction the game is walking.

The motherboard I'm using is the MSI KM2M Combo-L, which I've updated wit the latest available BIOS.

EDIT4: This seems to only be an issue in MS-DOS mode. If I play the games from Windows there's no issue.

You didn't mention this, but you don't also happen to have a joystick controller of some sort connected to do you? This happen to me all the time in Dosbox on my modern PC when I have my controller enabled or plugged in. Also not sure where to find this now, but way bitd I used to have an Alps glide pad when that was a new thing and could be bought standalone in the mid 90s. Anyway, I found that he glide pad driver took up much less memory than my standard microsoft mouse driver did and yet it still seemed to work with pretty much any PS2 mouse I plugged into the system at the time. So for games like Falcon 3.0 etc that needed as much of that 640k base frame memory as I could give it, it was a great help and eventually became my one and only mouse driver I needed. But I haven't fired up an actual DOS PC for many years now so I don't believe I have a copy of that old driver on hand anywhere these days. Still might see if you can locate it somewhere and see if it helps.

Hi, CrossBow777. Thank you for your reply.

No, I do not have any controller connected. The only peripherals connected are the mouse and keyboard. I've also tried running DOS mode without sound and/or CD-ROM support, but the issue remains.
I've been searching a bit for the Microsoft mouse driver, but I've not found it as of yet. I'm sure I can track it down though, if I look a bit more. I'll give it a go if I can find it and report back.

Use the A and D buttons to turn, not strafe.

See if any of these will help:

http://www.uwe-sieber.de/util_e.html

Has a few versions of the M$ mouse.com driver in there as well. I also remembered that I used to load my mouse driver in himem. For the record, I had a very unique 286 back in the day that was able to load both XMS and EMS drivers for the whopping 5mb of memory I had installed in it.

Stretch wrote:

Use the A and D buttons to turn, not strafe.

I might as well cut off an arm or two as well... 😉 I've been using a WASD + mouse configuration in FPS games for two decades. Going back to keyboard turning and aiming is not an option. The mouse and keyboard combo works fine for the games when running in Windows and I'm sure I'll be able to fix the issue in DOS.

CrossBow777 wrote:

See if any of these will help:

http://www.uwe-sieber.de/util_e.html

Has a few versions of the M$ mouse.com driver in there as well. I also remembered that I used to load my mouse driver in himem. For the record, I had a very unique 286 back in the day that was able to load both XMS and EMS drivers for the whopping 5mb of memory I had installed in it.

Cheers! I'll give those a go and report back. 😀

I have experienced the same behavior as you and it was posted in the forum many years ago to use the turn keys instead of the strafe keys to solve this issue.

Can you try to completely go the PS/2 route with both mouse and keyboard and then disable USB legacy in the BIOS?

Stretch wrote:

I have experienced the same behavior as you and it was posted in the forum many years ago to use the turn keys instead of the strafe keys to solve this issue.

I understand. As stated, it works fine if I run the game through Windows, so I can play it, if I want to. At this point it's more down to solving the issue, just because, more than playing the actual game(s).

It seems the system is unable to handle all the key presses and mouse movement at once. As it will get stuck if I press too many keys, like forwards, strafe and run, and then turn with the mouse. If I just move in one direction and turn, it's no problem. It's like the system gets overloaded with input. I've tried different memory configurations, thinking it's due to resource limits, but it's the same across the board using expanded, extended and conventional memory.

Rawit wrote:

Can you try to completely go the PS/2 route with both mouse and keyboard and then disable USB legacy in the BIOS?

I would try this, if I had two PS/2 adapters, or a PS/2 keyboard, or mouse. But I only have one adapter and all my mice and keyboards are USB. I'll see if I can get hold of a second adapter and give it a go.

I gave the MS mouse driver a go too, but the problem remains, so I don't think the issue lies with the mouse driver, but somewhere else. I'll keep on experimenting and see what happens.

Thanks for all the suggestions and help so far.