Re: [hatari-devel] Monochrome bug with latest Hatari

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 28/12/2015 09:51, Thomas Huth a écrit :

> > patch tested, I confirm it's better. Regarding the main part, it's
> > indeed still broken, but maybe that's something else than the
> > conversion functions.
>
> I haven't looked into it yet, but I guess the demo is using some video
> tricks like writing to the screen counter registers during HBL. So that
> needs to convert the buffer which is updated on each HBL instead of
> converting the buffer in the ST RAM - i.e. replacing "VideoBase" in
> above code with pSTScreen should basically fix this problem.
> ... but I'd like to double-check some possible issues first before
> committing that, to make sure that there are no other problems left
> (i.e. I first need some spare time for that).

Hi

the demo is indeed using timer B interrupts to change video address 
during display and create several area with different effects.

I had a look at the code, and the mono convert function won't work in 
that case, because it expects the screen to start at VideoBase and have 
a normal layout (which is OK for VDI). As you say, pSTScreen should be 
used instead, this intermediate buffer will be correctly filled each 
time Video_CopyScreenLineMono is called.

There's another mono demo that removes bottom border (not yet supported 
in Hatari) and in that case current code won't work either.

Nicolas