VECTORLIST - The Mailing List For The Technical Discussion of Vector-Based Arcade Games

February_1999
RE: Stupid Asteroids Tricks...


From: Clay Cowgill ( )
Date: Thu Feb 25 1999 - 10:43:27 CST


> << I'll have to drag my notes in. I want to say it's $21B in RAM, but
> I
> could be wrong. I've got some more stuff mapped out too. Maybe Doug
> and I can collaborate and make a "reference" for hacking on the
> Asteroids platform. ;-) >>
>
I was off by one-- $21C

As near as I can tell the bit-mapping works something like:

D7 D6 D5 D4 D3 D2 D1 D0
 a x x x x i j k

a = UFO exploding when set
x = seems to cause the UFO to appear, haven't really figured it out
i = when set, makes the HUGE UFO
j = when set, makes the Large UFO
k = when set, makes the Small UFO

-Clay


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