From: Carsten Svaneborg <aazaqeaxa AT aafys DOT aaaku DOT aadkaaa>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Orbiting Spheres?
Date: Fri, 15 May 1998 22:37:21 +0200
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References: <000401bd75d9$069ac040$cf4b08c3 AT arthur>
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Arthur wrote:
> The problem's a lot more complex than using conservation of
> momentum, but it's sparked an idea... From using momentum
> you've got to apply all sorts of stuff like Newtonian Physics,
> restitution and that.
Yes, Newtons second law of motion for both the starship and
the sphere,  mA=F    where A is the 2d acceleration vector,
and F the force.

On the starship there is 3 forces acting, Gravity pointing
downward (or upward if your screen is upside down), the 
thrust pointing in the the forward direction, the pull
of the sphere, can be modeled as being a rigid rod, a spring,
or a wire connection, depending on preference.

A rod can transfer torque about the center of mass,
depending the mass and relative velocity of the 
starship and sphere. The difference being that a spring
will have a soft distance dependent force, and the wire
a step like distance dependent force (0 when slack, 
large (infinite) when taut).

> Is there an easy way of patching the keyboard to register a
> number of different keys (say 6) being pressed at the same
> time? Of course there is, but how is it done?
When a key is depressed a scancode is generated, and when
it's lifted another scancode is generated, so you would have
to grab the scan codes somehow and interprete them.
Isn't a IRQ generated each keypress?, so there must be an
interrupt handler, which could be intercepted.

Have you checked x2ftp.oulu.fi they have loads of
games programming code, probably also keyboard source.

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