I ran this game with the patch installed on my Socket 7 computer (using both P233MMX and K6-2+/450 CPUs) without any problems with the mouse and keyboard both in Windows 98 and DOS.

There's a similar thread about this issue. The last post at that thread has a workaround regarding the config file that may help you there.

Gmlb256 wrote on 2021-09-01, 13:38:

I ran this game with the patch installed on my Socket 7 computer (using both P233MMX and K6-2+/450 CPUs) without any problems with the mouse and keyboard both in Windows 98 and DOS.

There's a similar thread about this issue. The last post at that thread has a workaround regarding the config file that may help you there.

I may have to try a slower pentium , I'll put in a P233MMX and see what happens. Still like to find out why the patches keep giving
me that error.

I've not played this game yet, but it's on my "Play it one day" list. There is a fan-made engine recreation at:

https://github.com/Panzerschrek/Chasm-Reverse/releases

I found the link at:

https://www.pcgamingwiki.com/wiki/Chasm:_The_Rift

which is a great site for helping to get a PC game running.

That fan-made engine uses SDL2, so it won't work on Windows 98 which the OP is testing with.

The PCGamingWiki guide is focused into running the original game with DOSBox, but it does contain a modified PS10.EXE under "Performance Fix".

Is the issue related with a runtime error? The only thing that I know for sure is that game uses a 16-bit DPMI server from Borland.

buckeye wrote on 2021-09-01, 13:30:

... it plays the demo endlessly while the keyboard/mouse is inoperable. […]
Show full quote

... it plays the demo endlessly while the keyboard/mouse is inoperable.

...Guess this game is buggy
which explains it's lack of popularity compared to Duke3d, Shadow Warrior and etc. Anyone successful in getting
this to run on "real hardware"?

Oh yes... it is buggy.
So many bugs, that it became one of the few games I tossed into the trashcan soon after I bought it back then.

I hate this game for the sound-clicks on several audio cards including GUS.
You can not deactivate the GUS on startup for using a SB16 that has much less "CLICKS" in the audio.

dr.zeissler wrote on 2021-09-03, 08:43:

I hate this game for the sound-clicks on several audio cards including GUS.
You can not deactivate the GUS on startup for using a SB16 that has much less "CLICKS" in the audio.

One way to "disable" the GUS is to remove the ULTRASND environment prior running the game and then add it once again when finished. Quake has a similar problem there.