MartiusR: Sorry for offtop, but regarding Chasm: The Rift - wasn't this "beefed" version (adjusted to modern systems, due to its rather picky nature, even with DosBox) "released" in the internet by former developer of Chasm? I know that it's not automatically means that it's legal to download it, but it's usual scheme that former developer is releasing for free some if his game(s) - such as Dink Smallwood, S.W.I.N.E etc.
As far as i know Chasm wasn't released for free. Original developers showed zero interest in releasing the game anywhere, probably they don't have the source code as well.
There were two projects to sourceport it, only one project is more or less active called "PanzerChasm", latest version 0.3 (Google it if you are interested). It runs smoothly, about 120 FPS, a few files required from original game, music doesn't work, some intro speech is missing.
A few minor bugs here and there: gibs physics not accurate, level 15 can't be completed due to missing switch for raising platform, level 16 ending has no camera switch to the Time Judge, enemies shoot rockets with no auto aim seeking (they always fly straight), zombies can be killed without beheading and are much slower to react, Alien Captain shoot single blaster instead of rapid fire, Sphinx's sarcophagus destruction have issues (it will kill the player unless he escapes within a short period of time to teleporter), lastly OpenGL lighting maps are f@cked up (i prefer Software mode). Even on hard difficulty PanzerChasm is way too easy.
So
if you know something about free release of Chasm: The Rift please do tell me.
As for the DOSBox the game is runnable on my old machine with 60 FPS (CPU = max cycles, UNIVBE 5.1). All you need to do is to patch it first, however for many users patches don't patch it properly (error 200) in that case you need to manually edit one file or you can download it already edited. If you are interested i can give you all info you need to run that game under DOSBox.