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Coding > GBA SP questions...

#4258 - SmileyDude - Wed Mar 26, 2003 2:16 am

I have a few questions regarding the GBA SP.

    Is there anyway to programatically detect if you are running on the SP vs the original GBA?


    Are there any additional registers that allow you to programatically turn on/off the backlight without turning off the whole display?


    Is it possible to detect that the lid has closed (i.e, to go into sleep mode automatically)?


I'm affraid the answers are going to be no, but I figured it is worth a shot. I just dumped the BIOS on my SP and it is identical to the one from my other GBA, so it's safe to rule out any BIOS changes. But, there still might be some register additions that might allow detection, changing the light, etc, etc.

Any info would be much appreciated :)
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dennis

#4315 - Saj - Thu Mar 27, 2003 1:53 pm

From what I know, the GB SP is just a gameboy Advance with Nintendo's version of the AfterBurner (Front-light) Kit. THere aren't any changes to the operating system/rom/bios and there aren't any software controls for the light.

Check out :-

http://www.lik-sang.com/news.php?artc=2821

There is a 0.01% chance of me being wrong on this one though...
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#4317 - ihatejonnytoo - Thu Mar 27, 2003 3:03 pm

Shit the only thing different about the sp is the cool case and rechargeable battery...plus it give you another reason to buy more of nintendo's crap....(i'll probably get one.)

#4335 - SmileyDude - Fri Mar 28, 2003 3:55 pm

ihatejonnytoo wrote:
Shit the only thing different about the sp is the cool case and rechargeable battery...plus it give you another reason to buy more of nintendo's crap....(i'll probably get one.)


That sucks... I at least would've thought that they might add a few SP specific registers to it.

As far as getting the SP goes, I highly recommend it. It's much easier for me to use for deving purposes. Just the ability to plug it in is worth it. The light makes it easier, of course, to see in my dark coding spot :)

My only problem, so far, is that sometimes, if the MBV2 cable doesn't finish transfering (error from the mb proggy), I won't be able to turn the GBA back on until the cable is unplugged. It is very weird -- no power light, no nothing. But as soon as the cable is unplugged, everything works again. Freaked me out the first time it happened.
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dennis

#4337 - ampz - Fri Mar 28, 2003 4:25 pm

Might be related to the F2A issue?

#4395 - SmileyDude - Sat Mar 29, 2003 7:25 pm

ampz wrote:
Might be related to the F2A issue?


Hmm.. I don't know exactly what the F2A issue is, but after working a little more with my SP and MBV2 cable, I've been able to avoid this problem.

Basically, when the mb proggy exits on error, it doesn't reset the cable. If the GBA SP is off when the cable is in that state, it won't be able to turn on until the cable is unplugged. But, you can unplug the cable, turn on the SP, and plug the cable back in, and everything works fine.

Like I said, once you know about the problem, it's easy to work around. Just make sure that the GBA is ready to go for multiboot before running the command line proggy, and if by some chance you forget, just unplug the cable before turning on the GBA.
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dennis

#4396 - gbajunkie - Sat Mar 29, 2003 9:30 pm

From seeing Zelda played I believe you can change the light status programatically. At one point in the game Link is wandering outside in a storm, the screen does look as though it is having the light turned on and off to convey the lightning effect although this could just be some clever fading.

Could someone either confirm or deny this is happening?

If this is the case then it could be used to interesting effect in future games. I am sure turning the light on and off may drain the battery that little bit quicker however.
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www.gbajunkie.co.uk - GameBoy Advance Development

#4402 - mbcook - Sun Mar 30, 2003 12:30 am

Zelda does that on a normal GBA too. I beleive that what happens is that there is a layer that is solid black that is made semi transparent put over the image. When the lightning flashes, the layer is turned off giving the effect of a lightning flash. I seriously doubt that you could. What possible reason could you have to want to do that, that's not just a gimmick?
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--Michael

#4597 - jaymzjulian - Fri Apr 04, 2003 3:29 am

Saj wrote:
From what I know, the GB SP is just a gameboy Advance with Nintendo's version of the AfterBurner (Front-light) Kit. THere aren't any changes to the operating system/rom/bios and there aren't any software controls for the light.


nontheless there are reasons to detect it - the game I'm woirking on right now, for example, was always gamma corrected for a GBA, and it looked great there, but was horrible and washed out on a SP - so I make it optional, but having it default to the right GBA type would be really slick, as I'm sure you'd agree :-p

- jj

#5258 - Ravage - Wed Apr 23, 2003 10:01 pm

2.5-week old necropost, but I thought I would comment anyway...

1) Unfortunately, the main hardware is identical under the hood so there is no way to auto-detect whether you're running a standard GBA or an SP. However, some developers are including options in their upcoming titles that allow the player to manually switch whether they are using an SP or not, so that the game can make the proper visual adjustments for that fact.

2) I'm almost 100% positive the hardware will not let you turn the light off or on yourself, which I'm sure was done for the user's benefit (imagine little johnny playing with his GBA under the covers before bedtime, where the light is the only reason he can play, and suddenly the game turns off the light for him.) Or simply the fact that if a user never wanted their light on because they live someplace where they always have ideal lighting conditions, you turning their light on for them needlessly sucks away their batteries.

3) The closing mechanism on the SP doesn't contain any electronics, to my knowledge, so detecting when the system is closed or not isn't a feasible idea unfortunately. I know I wish it was though. :)