Re: [hatari-devel] Improved cycle counting / rasters for 16/32 MHz

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 06/08/2016 à 18:24, Thomas Huth a écrit :
> Am Wed, 3 Aug 2016 23:56:00 +0200
> schrieb Nicolas Pomarède <npomarede@xxxxxxxxxxxx>:
>
> > Hello
> >
> > I just committed some changes for some better cycle counting when
> > using x2 or x4 cpu speed. This should help later for better 68030
> > cycles accuracy.
>
>  Hi Nicolas,
>
> thanks, that's pretty cool news! I guess we could now also have a more
> cycle-exact 68060 mode now (where most instructions are supposed to
> take one cycle)? Or emulate more than 32 MHz (like 64 MHz or 128 MHz)?

Hi

yes, by multiplying other components' clock instead of dividing number 
of cpu cycle, it means we can have higher cpu clock without loosing 
precision (for example <<3 or <<4) ; we could even do x1.5 (non integer 
values), but that would be slower than using << to shift values)

As for a better 68060 emulation, as the 68060 mode takes 1 cycle for all 
instructions at the moment, this would not give a real accuracy gain. 
But at least you would see that a 68060 running at 32 MHz is really 
faster than a 68060 running at 16 MHz for example (before, you would get 
1 cycle in both cases and no speed difference in the end)

>  Thomas
>
>
> PS: It's been quite a while since the last public release ... do you
> already have any plans for a public version 2.0 ?

That's almost 1 year since Hatari 1.9 ; I don't have any plan now wrt a 
release date, but it would be nice to release someday.

In the current state, I don't think the devel version should be named 
2.0, I would call it 1.10 (as I don't think there're so many changes 
visible to the user) and keep 2.0 for the release were Falcon cycles are 
really accurate (including correct cycle ratio with DSP)

If we were to release a new version with current state, I think it could 
be made around mid september.

If we wait for progress in the 68030 CE mode for Falcon, it could be 
much later, maybe near end of the year (I have no clear idea of the time 
I can spend coding on this part in the next months).

Nicolas