Re: [hatari-devel] WinUAE Falcon emulation and FPU

[Thomas Huth <th.huth@xxxxxx>]

Am Fri, 28 Sep 2012 23:12:52 +0300
schrieb Eero Tamminen <oak@xxxxxxxxxxxxxx>:

> On perjantai 28 syyskuu 2012, Thomas Huth wrote:
> > schrieb Eero Tamminen <oak@xxxxxxxxxxxxxx>:
> > > The reason seems to be that WinUAE core defaults
> > > FPU to "none".  If I select any other FPU option,
> > > the demo works fine.
> > > 
> > > Does old UAE core 030 setting emulate FPU?
> > 
> > Yes, that's why the GUI says "68EC030+FPU" when you
> > select this CPU level.
> 
> Why old UAE core emulates by default something which
> isn't standard on 030?

Because UAE means U* _Amiga_ Emulator, not U* _Atari_ Emulator ;-)
More precisely, it originally also did not really emulate
a 68030, but a 68020+FPU only, so this CPU level was rather used
to enable the FPU for 68020 in the old UAE core. But since some people
complained about that a Falcon rather needs a 68030, we upgraded it to
68EC030+FPU at one point in time :-)

> > > As Falcon has 68030 which doesn't include FPU and
> > > Falcon didn't include a separate FPU, how this demo
> > > can work on real Falcon?
> > 
> > It doesn't work on a non-FPU Falcon. Just read the
> > read_me.1st file that is shipped with the demo.
[...]
> IMHO it would be better to add something about that
> at least to the compatibility list.  These kinds of
> differences between our emulation cores can be a bit
> surprising...

Agreed, for such rare cases where it is not very obvious that
that a program needs an FPU, it might be helpful to have a
comment about that in the compatibility list. Could you add it?

> Are there a lot of demos that *require* FPU?

Not that I am aware of, only some very few I guess.

 Thomas