Re: [hatari-devel] cfg (8 vs 16 Mhz)

[Thomas Huth <th.huth@xxxxxxxxx>]

Am Fri, 2 Dec 2022 22:47:40 +0200
schrieb Eero Tamminen <oak@xxxxxxxxxxxxxx>:

> Hi,
> 
> On 2.12.2022 18.38, Miguel Saro wrote:
> > I note that whatever the set frequency (nCpuFreq = 16)
> > the starting frequency is always 8 Mhz
> > 
> > I don't know if it's intentional or if it's a small mistake.
> > I also don't know if it only happens on Mac or on all machines  
> 
> Hatari should be overriding frequency only when you explicitly ask it to 
> set specific frequency, ask it to set given machine type, or you've 
> specified conflicting settings requiring Hatari to change machine type 
> to resolve it.
> 
> Are you doing any of those?
> 
> Note: for these machine type options freq seems to default to 8Mhz:
> 	--machine st|ste|megast|megaste
> 
> 
> However, in case of MegaSTE (and Falcon) machines, also Atari side SW 
> can switch frequency between 8 and 16 MHz:
> https://git.tuxfamily.org/hatari/hatari.git/tree/src/ioMemTabSTE.c#n31
> 
> Do you have some Atari AUTO folder / ACC / CPX / desktop setting that 
> would set machine frequency to 8Mhz?

As far as I know, on a real Mega STE, the machine comes up in 8 MHz by
default, and you need the CPX to switch to 16 MHz. See e.g. also here:

https://forums.atariage.com/topic/181171-understanding-the-mega-ste/#comment-2268970

> Nicolas, I'm not sure whether Atari SW being able to change Hatari's own 
> settings for MegaSTE & Falcon machines types like this makes sense.
> 
> I think only emulated freq should be changed, not the configuration value.

Not sure whether we should change it ... I wonder whether people would
start complaining that the frequency setting in Hatari's GUI doesn't match
with the frequency that they set in their CPX?

Anyway, we should maybe add some more wording to the documentation about
the switchable frequency on the Mega STE and Falcon, I guess.

 Thomas