Log message:
Initial import of xsc-1.5:

XSC is a clone of the old Star Castle video game by Cinematronics.
Most of the details are from memory and a few old video game books
I have kicking around from the golden days.  This is just a fun
hack that I've been working on off and on for quite a long time.
I don't have any grand plans for it, except to hack on it when I
feel like it.  It's always good to have something like this available
when you feel like flying around and blasting the crap out of some
alien bad guy for a few minutes.