PDP-1 Spacewar! program internals

[Jim Leonard]

Al Kossow wrote:
> Russell:  I suspect most of them figured out the "basic trick", but I'm not sure.
> 
> Kossow: What "basic trick" were you thinking of?
> 
> Russell: That you could do everything based on the spaceship unit vector.

I'm afraid I don't understand what he's getting at.  Can someone explain 
the "basic trick" in a bit more detail?
-- 
Jim Leonard (trixter at oldskool.org)            http://www.oldskool.org/
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