Re: [hatari-devel] VBL warnings from Hatari on MegaSTE 8->16Mhz change

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 04/06/2025 à 20:47, Eero Tamminen a écrit :
> Hi,
>
> On 3.6.2025 23.31, Nicolas Pomarède wrote:
> > Le 26/05/2025 à 13:29, Eero Tamminen a écrit :
> > > I mailed the CPX.
> >
> > the issue was in fact general to any machine, not just MegaSTE, as 
> > soon as CPU speed was changed on the fly (without a subsequent reset). 
> > The cycle counter related to the current VBL was then offset by 64/68 
> > cycles during the current VBL.
> >
> > This was harmless but it's fixed anyway with a somewhat 
> > smaller/cleaner code than before
>
> Thanks!
>
> I tested switching (MegaSTE) CPU speed both by using GENERAL.CPX (in 
> desktop), and with debugger "setopt --cpuclock <x>" command (during 
> STDOOM demo playback), and both worked fine.
>
> => will add autostart support also to CPU clock option.

Hi

BTW,  I wrote a small program a few months ago when implementing 
MegaSTE's cache. It will toggle between 8 MHz and 16 MHz with cache on 
each run.

It's just reading then writing FF8E21, pretty simple behaviour

I'm attaching it here in case it can be useful to others

Nicolas

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