Amiga.org
Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: zosodk69 on March 30, 2008, 05:12:37 PM
-
I'm mostly happy with the performance of my rig. I am, however, having some performance issues with some games. Examples of games that are misbehaving are Turrican 2 and Cybercon III. In Turrican's case the symptoms are choppy scrolling/animation and slower music. In the case of Cybercon III the frame rate is darn near 2 fps.
Without the CSPPC the machine is running a 030/16 and both of these games run great. I've been back and forth with Bert Jahn (the author of WHDLoad) who indicates that this has to do with the "cachebility" of chip-memory. Here's a chunk of our conversation:
On Tue, May 01, 2007 at 02:14:45PM +0200, Bert Jahn wrote:
> the reason for running slower is probably that your csppc board does
> not support the cachebility of chipmem. In that case you should use
> the option ChipNoCache in s:whdload.prefs. With that it should run a
> bit faster but maybe not as fast as on your 68030.
> there is nothing more I can do because of that, sorry.
He's right! Adding ChipNoCache to my whdload.prefs changed the symptoms. Turrican 2 is now running at full speed. Cybercon III is better, but on my 060/60 it's still running a third the speed of the naked A3000 (030/16).
I've spent many months lurking and am quite impressed by how "hardware inclined" much of the Amiga community is.
I guess I'm curious why only some CSPPC boards have this defect. Could there be some sort of hardware or software fix to this issue; something as easy as an INT2 mod, maybe? :shrug:
-
my 2xcsppc are the same, and my 060 bppc was the same too. this is a 060 (and 040 perhaps) problem ...
-
I don't think it affects all cards though.
On Mon, May 07, 2007 at 09:30:45AM +0200, Bert Jahn wrote:
> I assume the reason is the card, because only some cards are affected.
> my csppc on a4000 works fine.
-
I doubt it.
by bppc was a DCE rev2 one.
Also had a DCE CSPPC, had the same prob
and my current 2 Phase5 csppc's have this too.
it is a 060 limitation
-
Interesting...
Could games like Cybercon III be WHDLoad hacked around this problem? I'm a bit ignorant of assembler but I've been quite impressed at how many games have been fixed to run on AGA/2mb chip/060 systems.
-
It's a known issue that many whdload slaves have issues with '040/060 cards.
My Cyberstorm MKII '040 % '060 has problems too...
-
Actually I lack knowledge of '040/060 cache mechanisms, but on x86 CPUs it's possible to activate/deactivate memory caching regions by changing the appropriate table (often it's a BIOS option for gfx mem).
Is this possibly done in the 68040.library's initialization?
-
Maybe you can use PPC UAE, to emulate a 030 ?
-
Sorry to drudge up this issue again; I've very anxious come to some sort of work-around to this. One of the primary reasons I still use my Amiga is gaming. It's extremely annoying that the most advanced accelerator you can own on a classic Amiga is a hindrance to this.
How feasible is it to run UAE on under OS 3.x at an acceptable performance level? Also, where can I find a PPC version of UAE that runs on 3.x?