GP2X The Coprocessor


STTrife

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A few general (and maybe stupid) questions about the co-processor of the Gp2X (the ARM940T)

I know it's used for video-decoding (Right?) but what else is it used for,
or what else CAN it be used for?
Are there any emulators/games that use the coprocessor?
Is it USEFULL for games/emus to use it?
Could it be possible to use it as some sort of GPU? like writing a 3d library that uses the coprocessor to do the 3d maths?
And ehh how can you give instructions to the ARM940T in C or C++ ?

I'm just not really into hardware but I still wonder about these stuff because I love my GP2X ;)
 

slygamer

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It can be used for anything you could think of using a 2nd processor for.
Some people are already using it like a GPU for rendering 3D polygons.
Take a look at the stickied demo tutorial thread in this forum for examples on how to use the 940T.
 

Trenki

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Instead of using only the one or the other CPU for doing graphics stuff like rendering of polygons one could use both and do some load balancing like NVidia does with SLI. I think this would give the best performance for 3D rendering.
 

Radek

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A few general (and maybe stupid) questions about the co-processor of the Gp2X (the ARM940T)

I know it's used for video-decoding (Right?) but what else is it used for,
or what else CAN it be used for?

Not exactly - it's used for video data parsing as the main task of video decoding is done by one of the other GP2x's coprocessor - the VideoProcessor
(and there some others too)

Are there any emulators/games that use the coprocessor?

Some are trying - I know about that Jaguar emu. I'm not that up the date thought, sorry.

Is it USEFULL for games/emus to use it?

Oh yes - it certainly can! It needs some carefull programming however. Not atypical for multicore type systems thought.

Could it be possible to use it as some sort of GPU? like writing a 3d library that uses the coprocessor to do the 3d maths?

Well... it just the same as the 920T in RAW power but with less cache and not MMU unit. It's entirely possible it could speed up such tasks like 3d maths. But it will not not match a dedicated hardware GPU, no chances for that.

And ehh how can you give instructions to the ARM940T in C or C++ ?

A very good topic (on others things too):
http://www.gp32x.de/board/index.php?showt...=27433&st=0

I'm just not really into hardware but I still wonder about these stuff because I love my GP2X ;)

As 940T implications are interesting but there few other intriguing aspects of GP2x too. The Videoprocessor for an example - it looks being quite flexible and could be potentially used for other tasks than just video. But it's a very fresh territory...
 
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MadDog

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Could it be possible to use it as some sort of GPU?

Thats what i'm using it for in my game engine i'm coding. cube.zip

And ehh how can you give instructions to the ARM940T in C or C++ ?

I've added a section to the 'Using Visual C 2005 Express Edition' Wiki on how to target the 940 in Visual Studio 2005 (the free version)
Using Visual C 2005 Express Edition

I would recommend having a good read of the demo tut, its very good basis for using the 940. The 940 has smaller cache but as it has no MMU it does not need to read page tables so its not as bad as it seems. Depending on the tasks you give it I would expect there to be little difference to the 920.

We need a topic like this one pinned. Was going to say start a campain 'free the 940' but it looks like its being put to work by almost everyone! :)
 
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MadDog

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Thats what i'm using it for in my game engine i'm coding. cube.zip

Don't call it Cube. There is already a free open source FPS game/engine called Cube, and it is likely someone will port it to the GP2X.
LoL, that just the name of the test app. :lol: The engine is called K9 i've not setup the site yet as i'm still in beta, lots of supporting tools to code up.

Sorry, should have said what name the engine is called. ;)
 
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