Re: [hatari-devel] Color and scroller problems in Overdrive "Dragon" screen?

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 24/08/2012 22:50, Eero Tamminen a écrit :
> Hi,
>
> On perjantai 24 elokuu 2012, Nicolas Pomarède wrote:
> > Le 24/08/2012 20:09, Eero Tamminen a écrit :
> > > in the Overdrive demo:
> > > 	http://pouet.net/prod.php?which=11351
> > >
> > > "Dragon" screen.
> > >
> > > The spinning balls are green at bottom half
> > > of the screen, the bottom of the screen has
> > > some garbage pixels and scrolltext vertical
> > > position is wrong on right side of the screen.
> [...]
> > yes, this is a known problem, you can even see it mentioned in the
> > compatibility doc :)
>
> Oh, so it seems... :-)
>
> > The overscan uses non standard timings on the last line, which shift
> > display on the next screen where upper half has no left/right border
> > removal. This is on my todo list, but requires some major changes
> > despite its simple result.
>
> Are all the problems, including the color in the spinning balls,
> due to that?

Yes, in upper part, 2 planes are shifted, so the color are wrongs. Only 
in the bottom part are the colors OK (this is also what gives the 
feeling that the text scroll is not at the correct place, as it's 
shifted by 16 pixels)

As for the garbage pixel they're also due to an error in the demo : I 
guess the coder didn't have a monitor that displayed as many lines as 
Hatari does and he didn't notice the last 6 lines or so were not in 
overscan as they should.

On a personnal note, I never liked this screen back in the days, rather 
ugly IMHO.

Nicolas