Re: [hatari-devel] DMA sound and Falcon

[Laurent Sallafranque <laurent.sallafranque@xxxxxxx>]

Hi Nicolas,

Thanks a lot, this version sounds like the hatari 1.7 version.
That's much better now ;)

Regards
Laurent




Le 12/09/2016 à 18:17, Nicolas Pomarède a écrit :
> Le 12/09/2016 à 15:11, laurent.sallafranque@xxxxxxx a écrit :
> > > I can fix this issue rather easily, I just need to take CpuFreqShift
> > into account, but it won't fix the case where starting the same program
> > at 16 Mhz sometimes gives correct sound and sometimes gives noisy sound.
> >
> >
> > Yes, that's what I expect for now.
> > I have more hope with the 68030 CPU improving (later) and memory 
> > access timings (later again).
>
> Hi
>
> I fixed falcon's crossbar to keep a constant sound rate when changing 
> CPU freq at 8 MHz or 32 MHz.
>
> What is interesting is that if you change cpu freq while playing a 
> sound in "compatible STE dma mode" (for example between 16,8,16,8,...)
> the sound will sometimes be noisy, then it will be clear again, or it 
> will stay noisy all the time and so on.
>
> This randomness really looks to me as if some variables are 
> overflowing or are not correctly reset when computing the "steps" to 
> convert from the requested Falcon sound freq to the host sound freq.
>
> I will try to look at this when I got more spare time.
>
> Nicolas