[hatari-devel] Blitter interrupt CPU usage

[Eero Tamminen]

Hi,

On Sunday 19 July 2009, Jean-Baptiste Berlioz wrote:
>  > 76% of CPU on my  machine when running the "Tribute to Rainbow TOS"
>  > demo from http://atari.freemind-tobe.com/.
>
> My nice little screen full of colors :) It use the blitter to change 2
> palette registers every 16 pixels.
>
> I did test it when i rewrote the blitter emulation, as far i as
> remember, the extra cpu load was caused by abusing the palette registers.

At least currently it's caused by the Blitter interrupts (palette stuff
shows up too, but its effect is much less).


> > The Hatari compatibility.html page lists couple of demos where the
> > blitter timing isn't yet accurate enough.
>
> Ah ok i must have a look at this :)
>
> It would be easier if blitter-addicts communicate their blitter settings
> when they notice wrong timings. I'll try to get some informations on
> #atariscne this evening.

According to the Compatibility list, the problematic cases are:

* E.P.S.S. Demo by Unit 17:
   http://www.pouet.net/prod.php?which=30912
   -> bottom border isn't right

* Extreme Rage by Anatomica:
  http://pouet.net/prod.php?which=15428

* Jam-Cols by Inner Circuit Explorers:
  http://www.pouet.net/prod.php?which=31452

* RGBeast by Aggression:
  http://pouet.net/prod.php?which=29355
  -> Not sure whether the issues come from blitter or overscan.
       (I don't have real STE, but the Youtube video of this looks
       impressive!)


	- Eero