Re: Re: Re: [stella] playfield on-the-fly updates

Subject: Re: Re: Re: [stella] playfield on-the-fly updates
From: Erik Mooney <emooney@xxxxxxxxxxxxxxxx>
Date: Wed, 13 May 1998 14:10:22 -0400 (EDT)
> >Q*bert and the enemy are obviously the two players.  Cube body is
> >playfield.  The flying discs are the unknowns.  If I remember correctly,
> >they flicker (only one disc on each row is displayed per frame), so I
> >guess we'd have to assume the discs are either missile or ball, and the
> >color is changed immediately before or after display.  (Notice the discs
> >don't move vertically - they disappear and Q*Bert just floats up to the
> >top by himself.)
> 
> No, the discs don't flicker, but change color - but that's not very
> important.

Sure, it's important.  If they flicker, that's one disc per line per
frame; if they don't, then it's two different objects.  Probably each
player's missile.
 
> That's not quite true. On scanlines with one, three or five cubes, the
> playfield isn't symmetric, so there have to be some playfield writes in
> there, too. I suppose they use different kernal parts for each cube
> level, that's twelve kernals in all, since the ones for cubetops and
> cube bodies are also different. Anyone confirm?

I'll hve to look at it when I get home... you've got me intrigued now 
here.  I think all the cube body kernels could be the same, since there
isn't any tricky timing going on during them.  (quick question - are the
discs at the level of cube tops or cube body?)

> >> And, in fact, Amidar uses three-color playfield, but it alternates
> >> colors by scanline, not by frame.
> >
> >Well, if you're gonna think *that* way, then there's games like Chopper
> >Command that have a thirty-colored playfield in the mountains :)
> 
> OK, so this doesn't seem to be an apprioriate example.
> 
> With love,
> Kurt Woloch

With love, and no witty signoff? :)


--
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/stella.html

Current Thread