[hatari-devel] Chaos AD problem : $fffffc02

[Nicolas Pomarède]

Le 13/06/2011 23:37, Laurent Sallafranque a écrit :
> I've checked the DSP part. Nothing special at first glance.
>
> I'll check it more.
>
> I think many sound problems may come from the fact that the real Falcon
> DMA sound has 2
> 32 bytes buffers.
>
> I've already thought about coding them in the crossbar, but I need some
> infos
>
> - when are these buffers filled by the Falcon ? (at VBL, every xxx
> cycles, ...)
> - Is there a "burst mode" like in the videl DMA ?
>
> I may try to read a few bytes every HBL, as Nicolas did for the STe and
> see if this increase the sound quality.
> (after 1.5)
>
> Regards
>
> Laurent

Hello

before doing that, you should check that the demos with bad sound are 
really writing in the same buffer that is being played.

If this is not the case (if the replay really uses double buffer), then 
the problem is certainly not related to an internal sound buffer or the 
need to update every HBL.

So, demo replays should be studied first to see if they use double 
buffer or not (easy to see : just check if sound start/end address is 
the same on every VBL or not) ; this first analysis is necessary to 
avoid spending time in some modifications that in the end might not 
improve anything.


Nicolas