[stella] Screensaver mode (was: Help (Timing problems?))

Subject: [stella] Screensaver mode (was: Help (Timing problems?))
From: "Thomas Jentzsch" <tjentzsch@xxxxxx>
Date: Thu, 2 Aug 2001 11:29:22 +0200
Andrew Davie wrote:
> > > BTW: I don't think a screensaver mode is necessary any more. And it
> > > "wastes" a lot of valuable space.
> >
> > If the game has the space left over, it goes a long way to adding that
> > little extra bit of retro authenticity.  It also performs a utilitarian
> > function, namely visually indicating when the game is over.  Space
> > Invaders
> > a good example of that.  I like the way the game kinda still runs in that
> > game even though the game is over.  It's like an "afterlife" mode.
> I concur.  Qb had an attract mode, as it is called, and it cost something
> like 10 bytes.

Ok, I see and agree. 

The difference between the coding of Qb and Starmaster is the number of used bytes.
In Starmaster EVERY color access is done like this:

  lda value
  eor screensaver_eor      ; 0 in normal mode, != 0 in screensaver mode
  and screensaver_mask   ; $ff in normal mode, $f7 in screensaver mode
  sta COLxx

So you need 4 extra bytes (and 6 extra cycles) for every color you want to set. Maybe there was a strict guideline, they had to do so. I don't think it is neccessary do it that strict. I should be enough to change only the colour of the major unanimated parts of the screen when the game is over. Normally these are the Background, PF and some constant player graphics. 

I haven't checked what happens in Qb, but i doubt, that with only 10 bytes the colors of ALL objects are altered.

So, just the effect off a screensaver should be enough for a retro look, right?

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

1.000.000 DM gewinnen - kostenlos tippen - http://millionenklick.web.de
IhrName@xxxxxx, 8MB Speicher, Verschluesselung - http://freemail.web.de

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

Current Thread