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

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 09/10/2019 à 21:04, Eero Tamminen a écrit :
> Hi,
>
> 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