Re: [stella] Supercharger screens...

Subject: Re: [stella] Supercharger screens...
From: bwmott@xxxxxxxxxxxx
Date: Sun, 10 Jan 1999 12:47:47 -0500 (EST)
> I think the progress bars to symbolize loading and maybe a flashing
> 'rewind' screen in cases where the BIN doesn't contain the requested
> load would be nice to have, especially since each SC-BIN contains
> a value for the progress bars and SC load time is very short in
> general.

Sound's like a good idea.  The progress bar shouldn't be hard to
emulate.  It looks like it's just a simpled mirrored playfield.  The
hardest thing will be getting the delay and sound to be right :-)

> I'm not so sure about a 'press play' screen, at least not if it
> requires user interaction. That might annoy people because it isn't
> really nessessary and it doesn't feel like starting a real tape
> player anyway.

I was thinking the user would NOT have to press anything, it would just
appear for a second or two and they jump to the progress bar screen.

> The problem with rewriting these screens is, that you might need some
> RAM, but I don't know which part of the RAM the SC uses for the starfield
> screen and which part of RAM it leaves intact. If Dan Boris really has
> the SC BIOS dumped, you might be able to get the real starfield routines
> out of it.

Based on Chris's Supercharger notes I would guess it uses the last page
of bank 1 for its RAM:

. . . . . PAGE 7 OF R1 IS USED
            FOR STARS AND MUST
            BE RELOADED (last page in bank 1 gets trashed when
                         doing multiloads)
> Would it be possible to have a line counter that counts the overall
> number of scanlines in a frame. You could output the number of scanlines
> for the last completed frame together with the number of frames per
> second when Stella exits to DOS.

I should be able to add this without to much trouble.

> And if you could update the handling of the multisprite trick, that
> would be very nice too. ;-)

I would love to get that trick fixed, however, I'm not sure there's
enough info on it to emulate it correctly.  Does anyone really understand
the multisprite trick and how it works?


Bradford W. Mott (bwmott@xxxxxxx)          Computer Science Department           North Carolina State University

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