Doom never runs at 60fps, at least if using the original vanilla engine. It is capped at 35fps. (same for Heretic, Hexen and Strife)

...well unless you count -timedemo mode.

Oh, wow ... I never knew that. Thanks for the information!

Was there any way to unlock the framerate or any "source ports" for the DOS/Win9x machines?

sofakng wrote on 2021-12-08, 16:36:

Was there any way to unlock the framerate or any "source ports" for the DOS/Win9x machines?

I know for sure DOS Boom and DOS MBF don't have uncapped framerate. DOSDoom and Doom Legacy I'm not sure about, last time I used either was too long ago, but my guess is no.

I'd say that if any DOS port which supports uncapped framerate exists, it's probably the one of the last DOS compatible versions of ZDoom.

grepping through the source code, it seems FastDoom can render uncapped but doesn't currently do interpolation between frames (so there's no visual benefit).

Personally I never liked how uncapped framerate in Doom ports feels, since without extensive modifications it has to be done using interpolation. Unfortunately, the whole original game logic was built around a fixed 35Hz timer...

edit: oh yeah, you mentioned Win9x too, I'm almost sure you can get a version of ZDoom which still runs on Win98SE at least (if not Win95) but already supports uncapped framerate with interpolation. The old Win9x compatible versions of JDoom/Doomsday may be able to do it too, if you're ok with an early hardware accelerated renderer which doesn't allow disabling texture filtering (=blurry textures and sprites everywhere) and incorrect lighting (common problem in all hardware rendered Doom ports before shader-based lighting was invented).

The original DOOM is perfectly smooth at 35FPS, and needs no more. Source ports for modern OSes may be another thing.

Last time I played Duke3D was last year, on a slot 1 Pentium III...I forget exactly how many MHz it was (500 maybe? edit: yes), but at 640x480, the game would have some slight slowdown in areas with too many slopes.