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DS development > It?s possible or Not? GBA emulator running on iPlayer

#169478 - darkchen - Thu Jul 16, 2009 3:32 am

iPlayer, a multi-media player on DS has been released for several days. A lot of people consider whether iPlayer could run a GBA emulator on DS. It is well know that running a GBA emulator on DS which is hard to be imaged before iPlayer release. Before iPlayer release people wish DS CPU is powerful enough to do that, but the CPU is not powerful enough to simulate GBA. Of course, Nintendo official have its solution, it is really not difficult to run GBA game on DS for official itself, but so far, it does not release any games fee paying downloading service yet, what is promised formerly. Further more, even though Nintendo official release GBA games downloading service, there will not be much too functions, such as screen shot, realtime save, frame skip, cheat and so on, what is included on common console emulators. PC emulator player should know these functions well.


Above all, I would like to introduce myself. I am not a professional programmer, but I am interested in programming. I pay a lot of attention on iPlayer news recently, and sent a mail to iPlayer official site to ask the possibility if GBA emulator could be launched by iPlayer, but unfortunately, according their reply, due to the copyright problems, iPlayer official will not provide GBA emulator. Yet, iPlayer really attract me, so I have bought one for researching.


In fact, simulating GBA is not very difficult. The principle is simple, using powered arithmetic capability to simulate a console circumstance, is similar to PC paltform console simulators. So to simulate GBA by iPlayer, the onboard CPU is indispensable. For a better effect of GBA simulating, the frequency of iPlayer onboard CPU have to be 20 times to GBA CPU, at least. Analyzing the ability of hardware decoding such high resolution videos, I suppose the onboard CPU?s frequency is not lower than PSP?s at least, even higher. Unfortunately, I have no detailed data about iPlayer, so these are just my hypothesize.


Logical analyzing:


The hardware of GBA includes two CPUs, one is a 32bit RISC instruction sets CPU (ARM7TDMI), which frequency is 16.78MHz, another one is 8bit CISC instruction sets CPU, a 130KB RAM, a 2D graphics card, six channel sound card, four channel DMA, four timers and so on. If count the GBA game card 256KB RAM on, the GBA system totally have 386KB RAM.


Then what we need to do is to simulate the hardware mentioned before. We must use our own instruction to simulate the ARM7 instruction system. On average, to simulate one instruction, need ten operations. In a word, iPlayer?s CPU frequency must be ten times to GBA?s, besides other hardware of GBA, there need to be another ten times. So totally twenty times, the iPlayer?s frequency must be 340MHZ or higher, and there must be enough RAM. According to the ability of hardware decoding AVI video, I believe iPlayer?s frequency will not be lower than PSP?s CPU which is 330MHZ, and iPlayer?s SDRAM should be 16MB or more, so running GBA emulator by iPlayer becomes possible.


Before writing, I mailed iPlayer official site again, wanting a SDK. I hope official will notice my post.

#169479 - TwentySeven - Thu Jul 16, 2009 4:39 am

...

*severe confusement*

...

Wait dude, what?

The NDS has hardware to run GBA games natively. Thats sort of the point of that big GBA CARTRIDGE SLOT on the bottom of the NDS and NDSL.

#169480 - darkchen - Thu Jul 16, 2009 5:10 am

TwentySeven wrote:
...

*severe confusement*

...

Wait dude, what?

The NDS has hardware to run GBA games natively. Thats sort of the point of that big GBA CARTRIDGE SLOT on the bottom of the NDS and NDSL.


yeah, surely there is for DSL and DS, but what's the solution for DSi? And there is no current flashcart compatible GBA emulator

#169481 - DiscoStew - Thu Jul 16, 2009 5:50 am

The website says that decoding is done on the flash card itself via a decoder chip. Doesn't say anything about the existance of a CPU that you mentioned.
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DS - It's all about DiscoStew

#169482 - elwing - Thu Jul 16, 2009 7:18 am

I think the 8bit CISC processor is only used for GB & GBC, and not present at all in the GBM & DS, thus not needed by GBA (don't take my words as the actual truth...)

#169483 - darkchen - Thu Jul 16, 2009 7:25 am

DiscoStew wrote:
The website says that decoding is done on the flash card itself via a decoder chip. Doesn't say anything about the existance of a CPU that you mentioned.


Sorry, I forgot to mention it, I have mailed to official site many times to discuss my idea, and I also have asked for the parameters of iplayer. fortunately they have replied, so I know actually there is a CPU in it.

#169484 - Dwedit - Thu Jul 16, 2009 12:16 pm

Sounds like a decoder chip would need to talk using the SPI interface, so there would be no real way to give something like that fast random access to memory necessary to emulate a GBA.
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"We are merely sprites that dance at the beck and call of our button pressing overlord."

#169485 - sonny_jim - Thu Jul 16, 2009 2:09 pm

Sheesh, why bother? Why not just buy a DS or GBA? There's much more interesting things that can be done with the iPlayer.

Quote:

I also have asked for the parameters of iplayer. fortunately they have replied, so I know actually there is a CPU in it.

Do you mean FPGA rather than CPU? Do you feel like sharing the 'parameters'?

EDIT:
Quote:

I believe iPlayer?s frequency will not be lower than PSP?s CPU which is 330MHZ

Why do you think this? It's a custom decoder chip, not an all purpose one so it won't need to run that quick.
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Quote:

Would that be the internet driver for the program?

#169490 - elwing - Fri Jul 17, 2009 6:13 am

that said as other said, buy yourself a GBM, it's just a marvelous machine...