Re: [stella] Star Fire Homepage

Subject: Re: [stella] Star Fire Homepage
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Thu, 23 Nov 2000 15:18:18 +0100
> ATM you can see few 2600 converted graphics and you can read what the
> original Star Fire programmer thinks about my plan to do his game on the
> VCS.

So, are you goint to tell us the URL of your page, or do you want
to keep it secret until you have some more contend up? ;-)
> A little question I've again about programming: When using the
> 6_different_sprites_in_a_line_without_flicker code, does that mean I can
> display _nothing_ else in these lines? What about the ball & the
> missiles? 
> I need to know that in order to decide how big I do the Exidy
> mothership. I mean, can I still display the starfield (Ball) and more
> important: the laser (Missiles) when drawing a moving 48 pixel
> mothership?

Unfortunately, the six sprites routine does take up every single
cycle in the scanline. If you could live with double scanline
resolution, you could free up some cacles in the second scanline.
And if the mothership has only one fixed graphics, you could use
indexed accesses instead of indirect-indexed addresses, which
would get you some more cycles. But the number of cycles that
you could get that way would only be enough to do really simple
things, like change a colour.

Also, since the mothership is supposed to be moving, the write
to the colour register (or whatever you do with the free cycles)
would also move and always happen for example right after the
ship has been drawn, no matter where on the screen that is.

And if you set up the sprites to three copies each with close
spacing, like you have to do for the six sprites routine, the
missiles will be set up that way too.

Ciao, Eckhard Stolberg

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