Rockbox Technical Forums

Support and General Use => Plugins/Viewers => Topic started by: n16ht5 on August 15, 2006, 02:33:00 AM

Title: gba support in rockboy?
Post by: n16ht5 on August 15, 2006, 02:33:00 AM
will ipod ever be able to play gba games? i have a bunch of gba roms...
Title: Re: gba support in rockboy?
Post by: Llorean on August 15, 2006, 02:33:27 AM
Probably not.
Title: Re: gba support in rockboy?
Post by: Suntiger on August 15, 2006, 03:41:36 PM
This is like saying "can you port Halo 2 to the Palm OS?"

Never going to happen. The chips in iPods are simply NOT POWERFUL ENOUGH.

I wish people could learn a rudimentary grasp of hardware requirements and stop asking these questions...
Title: Re: gba support in rockboy?
Post by: RotAtoR on August 15, 2006, 03:59:16 PM
I wish people could learn a rudimentary grasp of hardware requirements and stop asking these questions...

Easy there, I think it's a fair question to ask. ;) After all, Rockbox already supports GB and GBC, so GBA support may appear a logical extension. Even though the GBA is still a GameBoy, AFAIK it's more powerful than even the SNES system. It's highly doubtful that any of the current Rockbox targets could even emulate the SNES with decent speed. To put things into perspective, some people over at the ipodlinux project are having a tough time getting even the NES emulated well.
Title: Re: gba support in rockboy?
Post by: n16ht5 on August 16, 2006, 01:07:42 AM
i thought the ipod had some new chip that was supposed to be good/..? i have no idea what is in the ipod hardware.. and snes is extremely slow, even the playstation only had like a 133mhz processor or something
Title: Re: gba support in rockboy?
Post by: Llorean on August 16, 2006, 01:10:27 AM
The iPod is a 75mhz arm core. Fixed point math only.
Title: Re: gba support in rockboy?
Post by: Yotto on August 16, 2006, 01:57:03 AM
i thought the ipod had some new chip that was supposed to be good/..? i have no idea what is in the ipod hardware.. and snes is extremely slow, even the playstation only had like a 133mhz processor or something

The bigger the chip, the faster the battery drain.  Doesn't take that many mHz to play music.  I don't think the engineers at Apple expected you to want to turn it into a $300 gameboy emulator. :D
Title: Re: gba support in rockboy?
Post by: n16ht5 on August 17, 2006, 04:09:35 AM
pfft apple.. if only they had teamed up with sony on the psp...
Title: Re: gba support in rockboy?
Post by: Mathlar on August 17, 2006, 05:01:17 AM
The GBA only contains a single 17MHz ARM7 core.  In that respect the iPod has way more power...  But we lack the graphics hardware and nintendo are very good at exploiting that.

Just look at how the DS (with it's single ARM9 and ARM7 cop) plays Mario64... guess those funky 3D chips do a hell of a lot of work.
Title: Re: gba support in rockboy?
Post by: RotAtoR on August 17, 2006, 09:00:02 AM
The GBA only contains a single 17MHz ARM7 core.

And look at the original GameBoy, it only has a 4.19MHz Z80 processor and still can't be emulated at full speed on the ipods yet. Emulation requires at least an order of magnitude more work.
Title: Re: gba support in rockboy?
Post by: ZeRøB on August 17, 2006, 12:23:23 PM
VisualBoy Advance (a gba emulator for the PC) runs at 300-400% with a GBA game on one core from my computer (AMD Dual: 2x 2,2GHz)
Title: Re: gba support in rockboy?
Post by: Llorean on August 17, 2006, 02:31:16 PM
In terms of "way more power" we only have approximately 4 times the speed. In terms of emulation this is NOT a lot of space to work with.

As well, that's simply a comparison of raw computing frequency, and says nothing to the additional hardware in the Gameboy Advance.
Title: Re: gba support in rockboy?
Post by: travishayes89 on August 17, 2006, 04:54:34 PM
VisualBoy Advance (a gba emulator for the PC) runs at 300-400% with a GBA game on one core from my computer (AMD Dual: 2x 2,2GHz)

thats because desktop and laptop units are equipped with 3D graphics chips, and look at your cpu frequency, 2.2 GHz, versus the iPod Video's 75 MHz chip, and with a quick calculation on windows calculator , 2200 / 17 is approximately 117.64, thats a whole butt load of space to work with. why do you think you can run Windows Media Player while playing video games on some computers and not experience anything, but when you are playing music in Rockbox while playing bubbles, it skips like heck.
Title: Re: gba support in rockboy?
Post by: ZeRøB on August 17, 2006, 06:33:42 PM
That wasn't my point, my point was that even with 2,2GHz you can't run a GBA emulator very fast (300% isn't that fast if you think of it). 17MHz * 3 == 52MHz =! 2,2GHz
Title: Re: gba support in rockboy?
Post by: travishayes89 on August 18, 2006, 09:31:10 PM
but one thing, what would you do for buttons, the GBx (1980s/1990s), has 8 buttons, the GBA has 10, the DS has 12, 13 if you count the touchscreen, the iPod only has 7, and thats counting scrolling left and right as two different "buttons".
Title: Re: gba support in rockboy?
Post by: Llorean on August 18, 2006, 09:34:48 PM
You can pull off as many as 13 buttons on the iPod if you divide the scrollwheel into 8 regions, and count touching your finger to it in any of those regions, but NOT pressing the button beneath, as a button.

But the GBA is beyond the ability of the iPod to emulate, almost certainly, and the DS is well beyond it. Not even a question there.
Title: Re: gba support in rockboy?
Post by: ZeRøB on August 19, 2006, 06:05:47 AM
How do you want to press play without also touching play then? I just see 9 buttons possible. Maybe 10, if you make good use of the Hold switch (pauses game and gives option "Send thisandthis button").
Title: Re: gba support in rockboy?
Post by: travishayes89 on August 19, 2006, 07:46:56 AM
yeah, a DS emulator will have to wait until iPod 10 LoL, and well isn't the GBA screen also slightly larger, i can't tell, i lost the GBA i had, and besides, it started not to act right anyway.
Title: Re: gba support in rockboy?
Post by: Llorean on August 19, 2006, 03:29:49 PM
ZeR0B: One solution would be to have a very slight delay in reading the button, to give time for the button underneath to be pressed down.

In my case, my iPod skin has a ridge around the edge of the scrollwheel so I can press the buttons without triggering scrolls (very helpful for going to the next song without accidentally adjusting the volume).

Or the buttons could only trigger on release of the scrollwheel, which is a bit more awkward, but still offers them as available.

All I'm saying is there's a whole host of ways to get a few more pseudobuttons out if it were necessary.
Title: Re: gba support in rockboy?
Post by: travishayes89 on August 19, 2006, 10:40:12 PM
if that was possible, then we'd have a working GBx emu. and itd be kickbutt.
Title: Re: gba support in rockboy?
Post by: ZeRøB on August 20, 2006, 06:50:24 AM
But I don't think that ROCKbox wants to go the way iPodLinux goes, release a lot of semi working emulators that are slow, crash all the tie or just use half of the screen...
Title: Re: gba support in rockboy?
Post by: travishayes89 on August 20, 2006, 12:05:21 PM
yeah, ive used ipl, and iboy, even though it works, its slow, buggy, and does only use a quarter of the screen.
Title: Re: gba support in rockboy?
Post by: lareneg on August 20, 2006, 12:46:37 PM
I have an idea:

Buy a gameboy!

They're real cheap second hand now in gameshops. The games are rare, but you can get them
Title: Re: gba support in rockboy?
Post by: Jillorious on August 20, 2006, 01:35:19 PM
The iPod is a 75mhz arm core. Fixed point math only.
but if you people 'll find a way to put the broadcom chip into doing something useful, wouldn't that increase the units' power?
(based on my ignorant knowledge of this chip - in my minds eye it is simply like  adding more CPU power. Correct me if i'm wrong).
Title: Re: gba support in rockboy?
Post by: Llorean on August 20, 2006, 02:58:13 PM
Adding another processor doesn't really speed things up.

For example, imagine reading a book. Two people can't read one book twice as fast. Two people can read *two* books twice as fast though. With a lot of tasks, you're constrained to only applying one processor to it, due to the nature of the task. Even when you can apply two processors, having the communications between them work is incredibly complex.  Imagine cutting the book apart into chapters, and dividing the chapters between the two, but only one of them gets the chapter numbers, and has to tell the other one which chapter to read next, and get the summarized updates from him as to what has happened before he can continue reading his own chapters.

Right now, with the two-core processors Rockbox is likely to either keep everything on one-core, or handle everything *but* audio on one, and audio on the other. For video playback, the idea is to split video on one core and audio on the other. If the broadcom chip is ever enabled it'll probably be used to offload video to, since it's pretty much designed for this purpose and may not even be terribly useful for anything else.
Title: Re: gba support in rockboy?
Post by: Jillorious on August 20, 2006, 06:06:51 PM
Thanks for clarifying things.
but isn't this exactly what photoshop & other high-end computer programs are doing with the multi-core CPUs, simply "tearing apart the book" as you call it (much like a raid0 setup works for the hard drive)?
Title: Re: gba support in rockboy?
Post by: Llorean on August 20, 2006, 06:12:50 PM
In the case of something like the GBA emulator though, you only have one hard to divide task, that of pretending to be the GBA hardware.

For photoshop and others there are often multiple tasks that can be spread out, and their results returned.
Title: Re: gba support in rockboy?
Post by: SilleeString on August 24, 2006, 01:56:21 PM
If I'm not mistaken you can't split the task of emulating a GBA into different tasks (ie. GBA music, graphics, button input).  Any emulation (I believe) is one task as a whole, and I really highly doubt the iPod can run a working GBA emulator, let alone rendering the pseudo-3D graphics/sprites used in some of its games.