Chipsets

DamienD · 02 August 2005, 11:26

Hello all,

Wondering if somebody could help me out with information relating to chipsets?

Here's the deal... In the latest version of WinUAE (v1.0.0), for some games I have tried using "Cycle exact CPU and Blitter" and this works excellent for Defender of the Crown, It Came From the Desert, and It Came From the Desert 2.

On the other hand though I've tried this for Agony, Aladdin, Assassin, Assassin - Special Edition and had all sorts of troubles (ranging from slightly messed sprites to asking for disks when usually doesn't). I ended up using "Fast Copper" instead for these and all worked fine.

It's strange because for the 50 games that I've configured so far most seem fine with "Cycle exact CPU and Blitter" selected but there are just the few above that I've had to use "Fast Copper" for...

I don't really understand the difference between "Fast Copper" and "Cycle exact CPU and Blitter". Can anybody explain this to me? Also which is the best to use for the majority of games?

Toni Wilen · 02 August 2005, 15:37

Cycle exact is work in process, it will change in (nearly) every release. Sometimes previously working programs break and other previously broken start working etc. but it will get better slowly..

Fast copper: don't use it, not much speed improvement and usually causes problems.

Best game configuration: First A500 quickstart-setting with compatibility set to second highest position.

DamienD · 02 August 2005, 16:09

Many thanks for your response Toni. Much apprecaiated.

alexh · 02 August 2005, 18:45

Toni, I dunno if this is of any use for WinUAE

http://pasti.fxatari.com/68kdocs/index.html

It is the result of some work on the Atari ST 68000 emulators. It's helped further their development and enabled some demo's and copy protections to begin working.

It's an area of the 68000's behaviour not widely known.

Toni Wilen · 02 August 2005, 18:57

Quote:

Originally Posted by alexh

Toni, I dunno if this is of any use for WinUAE

http://pasti.fxatari.com/68kdocs/index.html

It is the result of some work on the Atari ST 68000 emulators. It's helped further their development and enabled some demo's and copy protections to begin working.

It's an area of the 68000's behaviour not widely known.

I knew about this long before it was published

DamienD · 04 August 2005, 12:21

Hello Toni,

I played around with some configurations yesterday and tried your suggestions. With for It Came From the Desert using "cycle exact" seemed to work slightly better than the "first A500 quickstart-setting with compatibility set to second highest position". For other games this was perfect... Anyway, I guess you just need to play around a bit with settings for different games and see how the performance is.

Also I know you said you shouldn't really use Fast Copper (and I'm taking you up on that suggestion) but I read somewhere on a FAQ sheet that "you can specify Fast Copper for those colourful rainbow graphic effects." Do you know what this means?

Many thanks.

Quote:

Originally Posted by Toni Wilen

Cycle exact is work in process, it will change in (nearly) every release. Sometimes previously working programs break and other previously broken start working etc. but it will get better slowly..

Fast copper: don't use it, not much speed improvement and usually causes problems.

Best game configuration: First A500 quickstart-setting with compatibility set to second highest position.

alexh · 04 August 2005, 14:06

I just think that is a dodgy FAQ.

AFAIK Fast Copper was a "different" implementation of the "Copper" co-processor found inside the Agnus / Alice chips. I am guessing it got it's speed, because it was written in faster (probably harder to read) code, which may or maynot have been a 100% accurate emulation.

Without Fast Copper selected, an alternate slower copper emulator is used.

I doubt that "Fast copper" is fast AND more accurate than the standard copper implementation.

With todays host CPU speeds, Toni has mentioned that the speed enhancment that "Fast Copper" has to offer is minimal, and far out weighed by the incompatibilities it introduces.

I am suprised the option for Fast Copper isn't dropped. I guess that the standard copper implementation is 100% accurate and sometimes this option can help?

DamienD · 04 August 2005, 14:25

Many thanks for the information alexh, that helps me understand a bit better.

(thank you also Toni for original suggestions)

02 August 2005, 11:26	#1
DamienD Banned Join Date: Aug 2005 Location: London / Sydney Age: 47 Posts: 20,420	Chipsets Hello all, Wondering if somebody could help me out with information relating to chipsets? Here's the deal... In the latest version of WinUAE (v1.0.0), for some games I have tried using "Cycle exact CPU and Blitter" and this works excellent for Defender of the Crown, It Came From the Desert, and It Came From the Desert 2. On the other hand though I've tried this for Agony, Aladdin, Assassin, Assassin - Special Edition and had all sorts of troubles (ranging from slightly messed sprites to asking for disks when usually doesn't). I ended up using "Fast Copper" instead for these and all worked fine. It's strange because for the 50 games that I've configured so far most seem fine with "Cycle exact CPU and Blitter" selected but there are just the few above that I've had to use "Fast Copper" for... I don't really understand the difference between "Fast Copper" and "Cycle exact CPU and Blitter". Can anybody explain this to me? Also which is the best to use for the majority of games?

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02 August 2005, 15:37	#2
Toni Wilen WinUAE developer Join Date: Aug 2001 Location: Hämeenlinna/Finland Age: 49 Posts: 26,519	Cycle exact is work in process, it will change in (nearly) every release. Sometimes previously working programs break and other previously broken start working etc. but it will get better slowly.. Fast copper: don't use it, not much speed improvement and usually causes problems. Best game configuration: First A500 quickstart-setting with compatibility set to second highest position.

02 August 2005, 16:09	#3
DamienD Banned Join Date: Aug 2005 Location: London / Sydney Age: 47 Posts: 20,420	Many thanks for your response Toni. Much apprecaiated.

02 August 2005, 18:45	#4
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,355	Toni, I dunno if this is of any use for WinUAE http://pasti.fxatari.com/68kdocs/index.html It is the result of some work on the Atari ST 68000 emulators. It's helped further their development and enabled some demo's and copy protections to begin working. It's an area of the 68000's behaviour not widely known.

04 August 2005, 14:06	#7
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,355	I just think that is a dodgy FAQ. AFAIK Fast Copper was a "different" implementation of the "Copper" co-processor found inside the Agnus / Alice chips. I am guessing it got it's speed, because it was written in faster (probably harder to read) code, which may or maynot have been a 100% accurate emulation. Without Fast Copper selected, an alternate slower copper emulator is used. I doubt that "Fast copper" is fast AND more accurate than the standard copper implementation. With todays host CPU speeds, Toni has mentioned that the speed enhancment that "Fast Copper" has to offer is minimal, and far out weighed by the incompatibilities it introduces. I am suprised the option for Fast Copper isn't dropped. I guess that the standard copper implementation is 100% accurate and sometimes this option can help?

04 August 2005, 14:25	#8
DamienD Banned Join Date: Aug 2005 Location: London / Sydney Age: 47 Posts: 20,420	Many thanks for the information alexh, that helps me understand a bit better. (thank you also Toni for original suggestions)

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