GBA add 2 buttons?

[fabulousmagician]

Hey you guys seem like you know your stuff so i was wondering:

    Would it be possible to add two more buttons to a gameboy advance sp and make it more like an SNES controller (mainly for the purpose of using an SNES emulator)

And does anyone know of any existing GBA SP mods and where i could find 'em?

Thanks a lot

[NFG]

the GBA is a poor SNES emulator, you're better off putting effort into the GP32.  That said, no, unless you can make a very significant hardware adaptor to add extra inputs to the GBA there's no four-button mod.

[fragment]

there is a mod where you can have the L and R buttons above the a and b buttons. I started a post, but didn't get much attention. It is possible for the regular Gameboy Advance, but the SP would be a little harder.

http://nfg.2y.net/forum/index.php?showtopi...st=0&#entry3556

[Martin]

Yeah, but what I think the guy meens is, is there anyway to make NEW buttons.. not meerly clone the L and R buttons.

[fragment]

i was discussing this in another forum once. If the emulator had a code that when L + A is intered it could be X, and R+B would be Y, then it would be possible. It just is unlikely that they programmers will do this. All you would have to do is hook up the new X and Y buttons to a L or R and a A or B. It is possible, but unlikely that they will add that to the SNES emulator. However, on Street Fighter Alpha 3, that game offers the 3rd set of punch and kick by combining L + A and R+ B, so you would at least have one game that uses that function. So it is possible...

[NFG]

yeah, but this screws any game where you'd normally want to press those buttons in combination, like a racing game where the shoulders are airbrakes.  It's a poor solution to the problem.  

Besides, if you're that hyped about a portable SNES, make one.

[fragment]

but if you didn't use the extra buttons, everything should work like normal? Also, you could also throw in a switch to enable/disable. Oh well, seams like no one is liking my ideas. I just want to know where to get buttons that small....

[Vertigo]

Buy a DS.

[Gummo]

It might be possible to add two more buttons...
Because of the D-pad, you can't physicaly press left AND right or up AND down at the same time. So, if you make a button that would press the left and right (and another one for up and down) at the same time, then a SNES emulator can check the registor that holds the button presses and if both left and right (up and down, too, as the Y button) are pressed, then the X button was pressed.

[NFG]

So, if you make a button that would press the left and right (and another one for up and down) at the same time

This worked on older systems like the FMTowns, but if you're going to apply it to new hardware you'd better find out first if it's able to handle it.  Suppose for example the GBA resets itself when both directions are pressed at the same time, assuming an error condition?

And then there's the little matter of games that require you to hold the button down.  How will you move your character around when LEFT and RIGHT are both held down by the new button?

On the FMTowns this wasn't an issue 'cause the two buttons that used this method were Start and Select, which are not held during play (And since it wasn't a retrofit there's no issue with software not expecting this behaviour).

[Gummo]

This worked on older systems like the FMTowns, but if you're going to apply it to new hardware you'd better find out first if it's able to handle it. Suppose for example the GBA resets itself when both directions are pressed at the same time, assuming an error condition?

I'm not sure, but I highly doubt anything else would happen other than both left and right being recorded as being pressed, but I can easily go test it out.  Are there any console (or handhelds) that would do something like that?

And then there's the little matter of games that require you to hold the button down. How will you move your character around when LEFT and RIGHT are both held down by the new button?

Good point, I didn't realize that. The reason I had tought up the idea of using left and right was because I had made a mod to my gba to play on an arcade machine. After playing some gba games on the arcade, I was thinking of a way that the gba could detect when a player had put quarters into the arcade.  So I came up with the idea of that when a quarter goes in, it would cause both left and right to be pressed, and I could test for that in a game.  Being as it would be a one time thing, I wouldn't have to worry about left and right to be held down too long and gameplay wouldn't be interferred with.  

I guess this really kills off the idea of adding 2 new buttons now.  However, I still have a feeling that there could be a way, just that it would be something really complicated or very tricky and ingenius to think of and to pull off.

[phreak97]

i have an idea of one of those very tricky ones.. this is entirely hypothetical and i would be very suprised if it actually gets done by anyone.. but im sure someone could use an inpt from the link port to work as extra buttons..  when tow gba's are linked, say in mario bros, both characters appear on both screens and 2p moves around on the 1p screen etc.. i dont know how much is possible, but possibly using the multiboot function of the gba (i dont know if it checks that during a normal boot) to load the driver into ram, which would then respond to signals coming in through the link port..
then you could write a program to go on a chip which could communicate via the link port.. although it could be difficult to fit it all inside the gba.
its a crazy idea.. but theoretically it might work.. even if only for one homebrew game..

it is possible to use another gba as a controller, if the game designer wants to.. making a chip to act as the other gba would be the hard part.. but you could have a whole load more buttons if you did.. although it would be a hell of a job to make the link port usable at the same time..

but like i said.. i never expect anyone to actually do it..

[Guest]

ok, this is the control setup for pocketsnes taken from their website:

SNES/GB
X    =    L      
A    =    R
R    =    Select+R
Y    =    B
B    =    A  
L     =    Select+L

So to have the full functionality of the pocketsnes emulator, you add two extra buttons, R that is wired to Select + R and L that is connected to Select + R.

Now if you are playing a game that lets you reconfigure the controls, you could have them properly mapped just like a SNES controller.


   
Seems like a funky setup, but it would be cool to have the extra buttons

http://www.pocketsnes.net/index.html