The spacebar is already bound, by default, to "jump". I have no idea if this key binding is hard-coded into the game or not. I would suggest to look at the default key binds to see if it can be changed.
In my defense I must tell you that I haven't been able to play the game for two years now and don't see any chance of that changing.
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Ahhhh, the vagueries of the aging mind. Wait.... What was I saying?
Carbonite <----- GitHub main module (Maps ONLY) download link. The other modules are also available on GitHub.
Carbonite-CLASSIC<----- GitHub link to Carbonite Classic. Thanks to ircdirk for this!