Yeah, fixed-time physics is the way to go. How you get that fixed time is
up to you, but it's a much better way than trying to put time into all of
your code. It is more stable, and easier to program as well. Since you are
thinking about lower end computers, you may have to rebalance everything for
a lower fixed-time update. (i.e, right now it runs good at 190 fps, but
that's probably not a good interval for a slower computer that can only run
60 fps). I think most professional games run at around 30 hz or so. I know
Doom3 did anyway, and that's the last I read about any game's update
function. Less than 30 though is probably not so good. On a really slow
computer, things will slow down, but you wouldn't want to skip too many
frames in that case anyway. If I can only run at 10fps, I would prefer the
game to update a little slower (slow motion) to having objects be warping
around.