| Re: [hatari-devel] Does CPU setting work? |
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On 30/06/2013 11:21, Miro Kropáček wrote:
Hi,
to my surprise, setting CPU to 16 or 32 MHz makes no difference in
performance of my CPU/DSP app at all (when I measure FPS for example). I
tried the "basic" Hatari only as Hatari/WinUAE is giving my a nice set
of bus errors and crashes with my DSP stuff.
Is this intentional/known fact?
Hello
I had a look to this, and the problem is in fact that TOS 4 will
configure bus speed during the boot to default 16 MHz by writing to
$ff8007 (it can be 8 MHz too in STF/STE compatible mode).
The status bar was not updated in that case, but cpu speed was changed.
What this means is that you can't start in Falcon mode directly at 32
MHz ; this is a non standard freq and it will be overwritten by the TOS
during the boot. You must change cpu freq later to 32 MHz, when gem
appears for example.
I committed a change to correctly update the status bar in case of a
write to $ff8007.
Nicolas