Re: [hatari-devel] "Desktop Info..." freezes with VDI mode

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

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Hi,

I experimented a bit with this and came up with the attached test patch.

Would it make sense to enable that stuff unconditionally for VDI?

I don't think it would slow it down noticeably and VDI mode isn't
significantly faster than normal ST/STE video mode anyway.


	- Eero

On 10/9/19 11:03 PM, Nicolas Pomarède wrote:
> Le 09/10/2019 à 21:04, Eero Tamminen a écrit :
> > I noticed that using "Desktop info..." from TOS versions
> > v1.04 - v1.62 freezes under color VDI modes.
> >
> > In non-VDI color modes, those TOS versions show color cycling
> > Atari logo in the Desktop info dialog which I assume to be
> > the problem.
> >
> > Profiler shows all cycles going to:
> > --------------------------------------------------------------------
> > $00e1c102 : move.b  d0,$fffffa21.w  33.31% (9791091, 156660216, 0, 0)
> > $00e1c106 : cmp.b   $fffffa21.w,d0  33.31% (9791093, 156661164, 0, 0)
> > $00e1c10a : bne.s   $e1c102         33.31% (9791092, 97915750, 0, 0)
> > --------------------------------------------------------------------
> >
> > Which seems to be waiting for the MFP timer B data register.
> >
> > Any idea why that wouldn't be advancing in VDI mode?
>
> Hi
>
> it's because of this in video.c :
>
> void Video_InterruptHandler_EndLine(void)
> {
>    ...
>          /* Ignore HBLs in VDI mode */
>          if (bUseVDIRes)
>                  return;
> }
>
> as the function returns, this means MFP_TimerB_EventCount() will not be 
> called, so fffa21 content will never change.
>
> But I think this code is there since several years already.
>
> Nicolas